Lung Cancer: Workup & General PrinciplesFrom Screening and Nodule Management Through Staging and Biomarkers
A peer-to-peer clinical reference covering LDCT screening criteria, Lung-RADS interpretation, Fleischner nodule follow-up, mediastinal staging indications, NSCLC pathology, essential molecular testing, TNM 9th Edition staging, MPE management, and lung cancer in the context of ILD.
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Lung Cancer Screening
Key Clinical Trial Data
| Trial | Population | Key Finding | Impact |
|---|---|---|---|
| NLST (USA) | Age 55–74, ≥30 pack-years | 20% relative reduction in lung cancer mortality; 6.7% reduction in all-cause mortality with LDCT vs CXR | Established the first global benchmark for LCS |
| NELSON (Dutch-Belgian) | High-risk smokers | 24% reduction in mortality (men), up to 33% (women) at 10 years; volume-based assessment reduced false-positive referral rate to 2.1% | Reinforced benefit in European context; established volumetry as preferred method |
| TALENT (Taiwan) | Never-smokers age 40–75; 50% with first-degree family history | 1.5% lung cancer detection rate in never-smokers with high-risk factors | Pivotal for Asian regions where EGFR-mutant never-smoker lung cancer is prevalent |
| FANSS (2025 update) | Asian-American female never-smokers | 1.3% detection rate; 100% of detected cancers harboured driver mutations (EGFR or HER2) | Highlights distinct biology of Asian never-smoker lung cancer cohort |
International Guidelines (April 2026)
USPSTF 2021
- Age 50–80 years
- ≥20 pack-year smoking history
- Current smoker or former smoker who quit within the last 15 years
- Annual LDCT
NCCN v2.2026 — Group 1
- Age 50–80 years
- ≥20 pack-year history
- Current smoker or quit within 15 years
- Annual LDCT; manage with Lung-RADS 2022
NCCN v2.2026 — Group 2
- Age ≥50 with ≥20 pack-years
- Plus one additional risk factor: COPD, occupational exposure (asbestos, radon, arsenic, silica), family history of lung cancer, personal history of cancer
ESMO 2025/2026
- Strongly recommends LDCT for high-risk smokers (similar to NCCN)
- Recommends volume-based screening software (NELSON-style) where available
- Emphasises integration with smoking cessation and MDT review of positives
PLCOm2012 (Tammemagi) Risk Model
A multivariable logistic regression model predicting the 6-year probability of developing lung cancer. Developed from the ever-smoker cohort of the PLCO Cancer Screening Trial. While PLCOm2012 is used to select who to screen, the PanCan/Brock model is used to manage nodules once found.
11 Predictor Variables
- Age (years)
- Education level (SES proxy)
- BMI (lower BMI paradoxically raises risk in smokers)
- COPD history (emphysema or chronic bronchitis)
- Personal history of any malignancy
- Family history of lung cancer (first-degree)
- Race/ethnicity (PLCOm2012-noRace version available)
- Smoking status (current vs. former)
- Smoking intensity (cigarettes/day)
- Smoking duration (years)
- Quit time (years since cessation)
Key Threshold
6-year risk ≥1.51% — globally accepted cutoff for screening eligibility (used in UK and Australian national programs)
Performance
- ILST: PLCOm2012 detected 99% of cancers vs 77% by USPSTF 2021 criteria
- Lower NNS than NLST criteria
- AUC ~0.80 even with PLCOm2012-noRace version
NCCN v2.2026 & ESMO Integration
NCCN explicitly recommends risk models like PLCOm2012 to identify individuals outside the strict age/pack-year criteria but with high risk from COPD or family history. ESMO prioritises risk-model-based selection (PLCOm2012) over categorical criteria, particularly for smokers who quit >15 years ago. Secondary models: PLCO2012results (incorporates baseline LDCT results); PLCOall2014 (adapted to include never-smokers).
PanCan (Brock) Model — Nodule Malignancy Risk
A 9-variable malignancy risk calculator for nodules identified on baseline LDCT. Consistently outperforms Lung-RADS v1.1 in specificity, reducing unnecessary procedures for benign nodules by ~25–30% (ILST 2025/2026).
9 Predictor Variables
- Age
- Sex (females: higher risk for given size)
- Family history of lung cancer
- Emphysema on CT
- Nodule size (largest diameter, mm)
- Nodule type (non-solid / part-solid / solid)
- Nodule location (upper lobe = higher risk)
- Nodule count (solitary nodule = higher malignancy risk for that nodule)
- Spiculation
Risk Thresholds & Management (2026)
| Brock Score | Management |
|---|---|
| <1.5% | Annual (or biennial) LDCT |
| 6–9% | 6-month follow-up LDCT |
| 10–29% | 3-month LDCT or PET-CT |
| ≥30% | MDT referral for biopsy or resection |
NCCN allows Brock as alternative to Lung-RADS for 6–15 mm nodules.
Lung-RADS v2026 Categories
| Category | Definition | Management | Malignancy Risk |
|---|---|---|---|
| 0 — Incomplete | Prior images required or scan technically incomplete | Obtain prior images or repeat LDCT | — |
| 1 — Negative | No nodules or definitely benign (fat-containing, complete calcification) | Annual LDCT in 12 months | <1% |
| 2 — Benign Appearance | Solid nodule <6 mm (new or baseline); pure GGO <30 mm; part-solid total diameter <6 mm | Annual LDCT in 12 months | <1% |
| 3 — Probably Benign | Solid nodule 6–<8 mm at baseline, or new nodule 3–<6 mm; pure GGO ≥30 mm; part-solid total ≥6 mm with solid component <6 mm | 6-month LDCT | 1–2% |
| 4A — Suspicious | Solid nodule 8–<15 mm at baseline, or new 6–<8 mm; part-solid with solid component 6–<8 mm; endobronchial nodule | 3-month LDCT or PET-CT if solid component ≥8 mm | 5–15% |
| 4B — Highly Suspicious | Solid nodule ≥15 mm, or new/growing ≥8 mm; part-solid with solid component ≥8 mm or new/growing solid component ≥4 mm | Tissue biopsy, PET-CT, or surgical resection | >15% |
| 4X — Highly Suspicious + Features | Category 3 or 4 nodule with additional suspicious features: spiculation, lymphadenopathy, doubling time <400 days, or high AI-probability score | Immediate diagnostic workup (PET-CT or biopsy) | >15% |
Fleischner Society 2026 — Incidental Nodule Follow-up
Solid Nodules — Single
| Size | Low Risk | High Risk |
|---|---|---|
| <6 mm | No routine follow-up | Optional CT at 12 months |
| 6–8 mm | CT at 6–12 months; consider CT at 18–24 months | CT at 6–12 months; then at 18–24 months |
| >8 mm | CT at 3 months, PET-CT, or biopsy based on AI/Brock score | CT at 3 months, PET-CT, or biopsy based on AI/Brock score |
Solid Nodules — Multiple
| Size | Low Risk | High Risk |
|---|---|---|
| <6 mm | No routine follow-up | Optional CT at 12 months |
| >6 mm | CT at 3–6 months; consider FU at 18–24 months if stable | CT at 3–6 months; FU at 18–24 months based on stability |
Subsolid Nodules (Ground Glass / Part-Solid)
| Type | Size | Management |
|---|---|---|
| Pure GGN (pGGN) | <6 mm | No routine follow-up |
| Pure GGN (pGGN) | >6 mm | CT at 6–12 months to confirm persistence; then every 2 years until 5 years |
| Part-solid | >6 mm | CT at 3–6 months to confirm persistence. If solid component >6 mm: PET-CT or resection |
NELSON 10-Year Data: Volume-based management reduces unnecessary biopsies compared to diameter-based management.
SUMMIT Study (2025/2026): For indeterminate nodules (6–8 mm), a positive ctDNA/protein marker panel increases priority for early biopsy.
AI-CAD (2026): NCCN now allows AI-CAD to replace manual measurements for nodules 5–15 mm, with 20% higher consistency in detecting interval growth.
GGO Follow-up Algorithm
Pure GGO (pGGN)
- <6 mm: No routine follow-up; optional 2- or 4-year check if very high risk or multiple
- ≥6 mm: Repeat CT at 6–12 months (confirm persistence vs. inflammatory); if unchanged, CT every 2 years for 5 years total
- Extended FU: NCCN 2026 suggests continued infrequent monitoring (every 3–5 years) for stable pGGNs >10 mm given very slow doubling times
Part-Solid GGO (mGGN)
- <6 mm: Treat like pGGN of same size; no routine FU
- ≥6 mm: CT at 3–6 months to confirm persistence
- If solid component <6 mm: Annual CT for 5 years
- If solid component ≥6 mm: Lung-RADS 4 / Fleischner high-risk → PET-CT, biopsy, or surgical resection
- Growth signal: Increase in solid component size is more significant than increase in total GGO size
JCOG0804: GGO-dominant lesions (solid <25%, size <2 cm) → sublobar resection (wedge) sufficient with 100% 5-year survival.
JCOG1211 (2025/2026 update): GGO-dominant lesions 2–3 cm → segmentectomy provides excellent local control, challenging need for lobectomy.
A-SURE Trial (2026): AI-volumetry detects 20% volume increase before 2 mm diameter change is visible to the human eye.
Low vs High Risk — Nodule Risk Stratification
High-Risk Features (Fleischner 2026 — Incidental)
- Current or former smoker (heavy pack-year history)
- First-degree family history of lung cancer
- Environmental exposure: asbestos, radon, uranium, silica, arsenic
- Brock Model probability >5%
- Nodule features: spiculated margins, upper lobe, older patient
Low-Risk Features (Fleischner 2026 — Incidental)
- Never-smoker or minimal exposure (<100 cigarettes lifetime)
- Younger patient (Fleischner applies to ≥35 years)
- Brock Model probability <5%
- Nodule features: smooth margins, non-upper lobe, perifissural (typically benign intrapulmonary LN)
2026 Risk Tools: Brock Model (PanCan) for nodule malignancy probability; AI-volumetry (VDT <400 days = high-risk growth); liquid biopsy MCED (SUMMIT 2025/2026) — positive ctDNA signal in indeterminate 6–8 mm nodule elevates to high-risk pathway.
Viva Cases — Screening
Case 1: The Heavy Smoker
Answer:
A 55-year-old male, current smoker (40 pack-years). He meets all three NCCN criteria: age 50–80, ≥20 pack-years, current smoker. Annual LDCT recommended; offer immediate smoking cessation support.
Case 2: The Former Smoker — Quit 16 Years Ago
Answer:
72-year-old, 30 pack-years, quit 16 years ago. Under NCCN 2026, technically outside the 15-year quit window. Decision should be individualised; PLCOm2012 may still show ≥1.51% risk. Benefit decreases as time-since-quitting increases.
Case 3: Asian Never-Smoker with Family History
Answer:
45-year-old HK Chinese female, never-smoker, mother and sister both had lung cancer at age 50. Not captured by NCCN population-based criteria, but TALENT trial data suggest 1.5% detection rate in never-smokers with first-degree family history. In HK context, discuss LDCT benefits and risks, highlighting high incidence of EGFR-mutant cancers in this demographic.
Case 4: 5 mm Nodule on LDCT
Answer:
A 5 mm solid pulmonary nodule in a high-risk smoker on screening LDCT = Lung-RADS 2 (benign appearance). Management: continue annual LDCT in 12 months.
Case 5: Harms of Screening Discussion
Answer:
Three primary risks for shared decision-making: (1) False positives — high rates of follow-up scans or invasive biopsies for non-cancerous findings; (2) Overdiagnosis — detecting slow-growing cancers that would never have caused symptoms; (3) Radiation exposure — cumulative risk from annual LDCT and follow-up procedures.
Case 6: PLCOm2012 — Long-Term Former Smoker
Answer:
68-year-old, 40 pack-years, quit 17 years ago. Under USPSTF 2021: not eligible (>15-year quit window). However, PLCOm2012 accounts for persistent risk in heavy former smokers. If PLCOm2012 score ≥1.51%, annual screening is recommended — supported by high-level evidence for mortality benefit even in this cohort.
Initial Workup of a Lung Mass
Based on NCCN v1.2026 and v2.2026 (NSCLC/SCLC), ESMO 2025/2026 Living Guidelines, and results from the LIBELULE (2026) and Lung-Care Project (2026) trials.
Initial Detection & Risk Stratification
- LDCT remains gold standard for screening (Lung-Care Project 2026: 55% mortality reduction even in non-traditional populations)
- Incidental nodules: managed via Fleischner 2026 (solid <6 mm → no FU in low-risk; >8 mm or growing subsolid → PET-CT or biopsy)
- Lung-RADS 2026: S modifier flags significant extrapulmonary findings (present in ~33% of scans)
Staging Workup
- Whole-body PET-CT: Essential for all patients considered for curative intent; identifies occult distant metastases
- Brain MRI with contrast: Mandatory for Stage IB or higher. In 2026, advanced DWI increasingly used to differentiate small metastases from benign lesions
- 9th Edition TNM focus: N2a (single-station) vs N2b (multi-station) dictates neoadjuvant chemo-IO vs definitive chemoradiation
Biopsy Approaches
| Method | Best For | Yield / Risk | Notes |
|---|---|---|---|
| Robotic-Assisted Bronchoscopy (RAB) — Ion / Monarch | Peripheral lesions | 75–80% diagnostic yield; lower pneumothorax risk than CT-guided | Preferred first-line for peripheral lesions in 2026 |
| CT-Guided TTNA | Very peripheral, subpleural lesions | High yield; ~15–20% pneumothorax risk | Second choice after RAB for peripheral nodules |
| EBUS-TBNA | Mediastinal/hilar nodes, central masses | High sensitivity; first-line for nodal staging | Obtain tissue from highest-stage disease first |
| Surgical (VATS / Thoracoscopy) | Peripheral nodules not accessible by bronchoscopy; diagnostic + therapeutic | Definitive; also allows pleurodesis if needed | Reserved if less invasive methods fail or nodule requires resection |
| Liquid Biopsy (ctDNA) | Suspected advanced NSCLC | Reduces time-to-treatment initiation by up to 16 days (LIBELULE 2026) | Initiate concurrently with tissue biopsy; negative plasma should trigger tissue testing |
Mediastinal Lymph Node Staging — Indications 2026
Invasive staging (EBUS-TBNA or EUS-FNA) required for:
- Mediastinal node ≥10 mm short-axis on CT or PET-avid
- Central tumour (inner one-third of hemithorax) — strongest predictor of occult N2 disease
- Any solid tumour >3 cm (cT2+) — even if PET-CT mediastinum negative
- Suspected N1 disease (enlarged or PET-avid hilar nodes) — 20–25% risk of occult N2 involvement
- Inconclusive PET-CT (equivocal uptake; granulomatous disease suspected, e.g., TB in HK context)
Exceptions (no invasive staging required):
- Peripheral tumour <3 cm (cT1a–c) with PET-CT negative mediastinum → proceed directly to surgical resection with systematic nodal dissection
9th Edition N2 Subdivision (High-Yield)
N2a: Single ipsilateral mediastinal station → T1N2a = Stage IIB (downstaged from IIIA in 8th edition)
N2b: Multiple ipsilateral mediastinal stations → T2N2b = Stage IIIB
This distinction dictates whether a patient is a candidate for primary surgery with adjuvant therapy vs. upfront neoadjuvant chemo-immunotherapy.
Viva Cases — Lung Mass Workup
Case 1: Mediastinal Staging Sequence
Answer:
A PET-CT shows a 3 cm LUL mass and a PET-avid station 7 node. Next step: EBUS-TBNA of station 7 first. If positive, patient is at least Stage IIIA (N2). Always obtain tissue from the highest stage of disease to avoid multiple procedures.
Case 2: The Negative EBUS
Answer:
High clinical suspicion of N2 disease (2 cm PET-positive node), but EBUS-TBNA was negative. Next step: surgical staging via mediastinoscopy to confirm the node is truly negative before proceeding to surgery. EBUS has a false-negative rate of ~10–20%.
Case 3: Peripheral Nodule Biopsy Method
Answer:
1.5 cm nodule in the extreme periphery of the right lower lobe: preferred method is Robotic-Assisted Bronchoscopy (RAB). Superior diagnostic yield for small peripheral lesions vs conventional navigation, and much lower pneumothorax risk vs CT-guided TTNA.
Case 4: Pre-Surgical Brain Imaging
Answer:
2.5 cm mass, no nodes, no symptoms — brain MRI still required. Per NCCN 2026, brain MRI is recommended for all Stage IB or higher patients. Even in Stage I, finding a solitary metastasis changes management from surgery to systemic therapy or SRS.
Pathology of NSCLC
Classification follows the WHO 5th Edition (Thoracic Tumours) and the IASLC 2020/2021 Grading System, the established standards for 2026.
Adenocarcinoma — ~50% of NSCLC
Pre-invasive Lesions
- AAH (Atypical Adenomatous Hyperplasia): Small (≤5 mm) proliferation of atypical pneumocytes
- AIS (Adenocarcinoma In Situ): Pure lepidic growth, no invasion, ≤30 mm. Size >3 cm is classified as Lepidic Predominant Adenocarcinoma — risk of occult invasion too high for AIS designation
- MIA (Minimally Invasive Adenocarcinoma): Predominantly lepidic with invasive component ≤5 mm
Invasive Adenocarcinoma Subtypes (Predominant Pattern)
| Pattern | Description | Grade Significance |
|---|---|---|
| Lepidic | Growth along alveolar walls | Low-grade (Grade 1 if predominant) |
| Acinar | Glandular formation | Intermediate (Grade 2 if predominant) |
| Papillary | Growth along fibrovascular cores | Intermediate (Grade 2 if predominant) |
| Micropapillary | Small clusters lacking fibrovascular cores | HIGH-GRADE — triggers Grade 3 if ≥20% |
| Solid | Sheets of cells with mucin production | HIGH-GRADE — triggers Grade 3 if ≥20% |
| Cribriform | Sieve-like appearance (added as high-grade 2020) | HIGH-GRADE — triggers Grade 3 if ≥20% |
IASLC Grading System (2020–2026 Standard)
- Grade 1: Lepidic predominant with <20% high-grade patterns (micropapillary, solid, cribriform)
- Grade 2: Acinar or Papillary predominant with <20% high-grade patterns
- Grade 3: Any tumour with ≥20% high-grade patterns — automatically Grade 3 regardless of predominant pattern
Squamous Cell Carcinoma
| Subtype | Features |
|---|---|
| Keratinizing | Presence of keratin pearls or intercellular bridges |
| Non-keratinizing | Lacks obvious keratinisation but expresses SCC markers (p40, CK5/6) |
| Basaloid | Distinct nested, peripheral palisading growth pattern; often carries worse prognosis |
IHC markers: p40 positive, p63 positive, CK5/6 positive.
Large Cell Carcinoma & Other Rare Subtypes
Large Cell Carcinoma (LCC): Undifferentiated NSCLC lacking morphological and IHC features of adenocarcinoma, SCC, or SCLC. This is a diagnosis of exclusion requiring a complete resection specimen — cannot be diagnosed on small biopsy. On core biopsy, use NSCLC-NOS or "NSCLC, favor [subtype]."
| Subtype | Key Features |
|---|---|
| Adenosquamous carcinoma | ≥10% each of adenocarcinoma and SCC components |
| Pleomorphic carcinoma | Most common sarcomatoid carcinoma |
| Spindle / Giant cell carcinoma | Sarcomatoid variants |
| Carcinosarcoma / Pulmonary blastoma | Epithelial + mesenchymal features |
| Thoracic SMARCA4-deficient undifferentiated tumour | Highly aggressive; young heavy smokers; TTF-1/p40/synaptophysin negative → request SMARCA4 (BRG1) IHC |
| Lymphoepithelial carcinoma | Undifferentiated; EBV-associated; more common in Asian populations |
Key IHC Markers
| Marker | Positive In | Notes |
|---|---|---|
| TTF-1 | Adenocarcinoma | Nuclear staining; also in thyroid tumours |
| Napsin A | Adenocarcinoma | Cytoplasmic; highly specific for lung origin |
| p40 | Squamous cell carcinoma | Most specific squamous marker; preferred over p63 |
| p63 | Squamous cell carcinoma | Less specific than p40 (also stains other tumours) |
| CK5/6 | Squamous cell carcinoma | Useful when p40 equivocal |
| SMARCA4 (BRG1) | Loss of expression in SMARCA4-deficient tumour | Order when TTF-1/p40/synaptophysin all negative in young smoker |
Viva Cases — Pathology
Case 1: NSCLC-NOS on core biopsy — can you diagnose Large Cell Carcinoma?
Answer:
No. Large Cell Carcinoma is a diagnosis of exclusion requiring a complete resection specimen to rule out any adenocarcinoma or squamous differentiation. On a small biopsy, the correct term is NSCLC-NOS or 'NSCLC, favor [subtype]' based on IHC.
Case 2: Adenocarcinoma Grading — 60% Acinar + 30% Solid
Answer:
Grade 3. Even though Acinar is the predominant pattern, the presence of ≥20% of a high-grade pattern (Solid) automatically upgrades the tumour from Grade 2 to Grade 3 per the IASLC 2020 grading system.
Case 3: 3.5 cm pure GGO — can this be pathologically staged as AIS?
Answer:
No. The WHO 5th Edition and TNM 9th Edition size limit for AIS is ≤30 mm (3 cm). A pure lepidic lesion >3 cm is classified as Lepidic Predominant Adenocarcinoma because the risk of occult invasion is higher in larger lesions.
Case 4: SMARCA4-deficient tumour workup
Answer:
40-year-old heavy smoker, massive undifferentiated mediastinal/lung mass, TTF-1/p40/synaptophysin all negative. Request SMARCA4 (BRG1) IHC. Loss of SMARCA4 expression confirms Thoracic SMARCA4-deficient undifferentiated tumour — a distinct, aggressive entity often found in this clinical demographic.
Essential Molecular Testing
Standard for all new stage IV non-squamous NSCLC and for non-smokers with stage III. Done via a comprehensive panel plus PD-L1 IHC. Preferred HK/SG workflow: comprehensive tissue DNA NGS (with copy-number) + RNA fusion panel + PD-L1 IHC simultaneously. Use plasma NGS when tissue is limited or biopsy risky; negative plasma should trigger tissue testing when feasible.
Tier 1 — Must-Test Biomarkers
| Biomarker | Incidence (Asian, advanced non-squamous) | Main Alteration | Preferred Test (HK/SG) | Key Notes |
|---|---|---|---|---|
| EGFR (ex19del, L858R, others) | ~35–50% | Activating SNVs/indels | DNA NGS (tissue) ± plasma NGS; RT-PCR if no NGS | Highest-yield target; ensure coverage of exons 18–21 and exon 20 insertions |
| EGFR exon 20 insertion | ~4–12% of EGFR+ | In-frame insertion | DNA NGS with good exon 20 coverage | Report separately from classical EGFR; dedicated drugs differ from standard TKIs (PAPILLON: amivantamab + chemo, PFS 11.4 vs 6.7 months) |
| ALK | ~3–7% | Gene fusion | RNA NGS fusion panel; ALK IHC (screen) ± FISH | Accept ALK IHC or NGS as actionable; reflex NGS at progression |
| ROS1 | ~1–3% | Gene fusion | RNA NGS; ROS1 IHC (screen) ± FISH | Rare but highly targetable; avoid relying on IHC alone if NGS available |
| BRAF (esp. V600E) | ~1–2% | SNV | DNA NGS | Report V600E separately; non-V600 variants flagged as 'non-classical' |
| KRAS (incl. G12C) | ~10–15% | SNV | DNA NGS | Call out G12C specifically; relevant for 2L targeted options (adagrasib, sotorasib) |
| MET exon 14 skipping | ~3–4% | Splice-skipping | RNA NGS preferred; DNA NGS with intronic coverage | Do not rely on MET IHC alone; critical to have RNA fusion/isoform assay in panel |
| RET fusions | ~1–2% | Gene fusion | RNA NGS | Selective RET inhibitors available; treat any canonical oncogenic fusion as actionable |
| HER2 (ERBB2) mutation | ~1–3% | In-frame insertion (ex20), SNVs | DNA NGS | Distinguish mutation from amplification; mutation is key target for TKIs/ADC |
| HER2 amplification / overexpression | ~2–3% | Copy-number gain, IHC 3+ | IHC ± ISH/FISH; NGS copy-number | Consider mainly in trial/ADC contexts; c-MET IHC 3+ now standard for Telisotuzumab Vedotin (approved 2025/2026) |
| NTRK1/2/3 fusions | <1% | Gene fusion | RNA NGS; pan-TRK IHC (screen) | Tissue-agnostic indication; include in fusion panel even though ultra-rare |
| PD-L1 (TPS) | ≥1% in ~50–60%; ≥50% in ~25–30% | Protein expression | IHC (22C3 or harmonised clone) | Essential for deciding IO vs chemo-IO vs TKIs; request on all new advanced cases |
Tier 2 — Strongly Recommended / Prognostic Markers
| Biomarker | Incidence (advanced NSCLC) | Alteration Type | Testing Method | Clinical Relevance |
|---|---|---|---|---|
| STK11 | ~15–20% | SNVs/indels | DNA NGS | May associate with IO resistance, 'cold' tumours; prognostic |
| KEAP1 | ~10–15% | SNVs/indels | DNA NGS | Poor-risk biology, potential IO resistance; useful for counselling |
| TP53 | ~50% | SNVs/indels | DNA NGS | General marker of genomic instability; co-alterations may influence prognosis |
| MET amplification (high-level) | ~1–3% de novo | Copy-number gain | DNA NGS copy-number; FISH if required | Actionability mainly at high-level amplification; define lab-specific cut-offs |
| TMB (tumour mutational burden) | ~10–20% 'high' | Composite | Large-panel DNA NGS | Optional adjunct for IO decisions; assay-dependent and not standalone |
PD-L1 TPS — Clones and Clinical Roles
| Clone | Platform | Associated Drug | Notes |
|---|---|---|---|
| 22C3 | Dako ASL48 | Pembrolizumab (Keytruda) — required for monotherapy | Standard for NSCLC TPS; harmonised with SP263 |
| 28-8 | Dako ASL48 | Nivolumab (Opdivo) + Ipilimumab | High concordance with 22C3 and SP263 |
| SP263 | Ventana | Durvalumab (Imfinzi); widely accepted for pembrolizumab/nivolumab | Largely interchangeable with 22C3 and 28-8 (Blueprint Project) |
| SP142 | Ventana | Atezolizumab (Tecentriq) — scores both TC and IC | Outlier: consistently stains fewer tumour cells; not interchangeable with 22C3 for pembrolizumab decisions |
| 73-10 | Dako | Avelumab (Bavencio) | Less commonly used in lung cancer |
PD-L1 TPS Interpretation — Clinical Decisions (NCCN v5.2026 / ESMO 2026)
| TPS | Advanced NSCLC (No Driver) | Early Stage (Perioperative) | SCLC |
|---|---|---|---|
| ≥50% | Single-agent PD-1/PD-L1 inhibitor preferred (pembrolizumab, atezolizumab, cemiplimab); chemo-IO option for high burden/symptomatic disease | Neoadjuvant chemo-IO regardless of PD-L1 (CheckMate 816 / KEYNOTE-671 / AEGEAN); higher PD-L1 → greater magnitude of benefit | PD-L1 testing NOT required; all eligible patients receive chemo-IO (IMpower133, CASPIAN) regardless of TPS |
| 1–49% | Combination chemo-IO is standard; monotherapy is allowed but often considered less effective | Same as above — benefit across all PD-L1 subgroups | — |
| <1% | Combination chemo-IO mandatory; single-agent IO generally not recommended | Same as above — TPS <1% does not disqualify from neoadjuvant IO | — |
Pleural Effusion Biomarkers — Cell Blocks vs Fluid
In 2026, malignant pleural effusion is not just a palliative challenge — it is a primary diagnostic resource and liquid biopsy equivalent.
Cell Block
Gold standard for cytology; allows IHC and resembles tissue architecture. NCCN V3.2026 mandates attempting a cell block on all MPE samples. PD-L1 TPS on cell block reliable if ≥100 viable tumour cells. Do NOT perform PD-L1 on smears or cytospins.
Supernatant (cfDNA)
Acellular fluid contains high concentrations of cfDNA and exosomes. Pleural fluid cfDNA sensitivity for driver mutations: ~85% vs ~65% for plasma cfDNA (2024–2025 trials). NGS on pleural fluid supernatant has >90% concordance with tissue NGS (ESMO 2026).
Extracellular Vesicles
Exosomes in pleural fluid can detect RNA-based fusions (ALK, ROS1) missed by DNA-only NGS. High cfDNA levels are prognostic — correlate with shorter PFS.
| Guideline | Recommendation |
|---|---|
| NCCN 2026 | If tissue biopsy risky or insufficient, pleural fluid (cell block + supernatant) is a Category 1 recommendation for molecular profiling |
| ESMO 2026 | Recommends 'reflex' molecular testing on the first positive cytology sample to avoid delays in treatment |
| UpToDate | Negative molecular result in pleural fluid should still be followed by tissue biopsy if clinically suspicious (to rule out false negatives) |
Viva Cases — Molecular Testing
Case 1: 100% PD-L1 — start pembrolizumab?
Answer:
Must wait for molecular driver testing (NGS) results. If EGFR or ALK found, targeted therapy is preferred first-line. Starting immunotherapy in a driver-positive patient is less effective and increases risk of severe toxicity (e.g., pneumonitis) if a TKI is used later.
Case 2: SP142 negative — sufficient to exclude pembrolizumab eligibility?
Answer:
No. SP142 is known to have lower sensitivity for tumour cell staining. To determine eligibility for pembrolizumab, the 22C3 clone (or a harmonised equivalent like SP263) should be used to calculate TPS.
Case 3: PD-L1 in Extensive-Stage SCLC = 0%
Answer:
Does not exclude durvalumab/chemotherapy. Based on CASPIAN and IMpower133 trials, PD-L1 expression is not predictive in SCLC. All eligible patients receive chemo-IO combination as first-line.
Case 4: Insufficient tissue for NGS but large MPE
Answer:
Perform therapeutic thoracentesis and submit for cell block (cytology + PD-L1 IHC if ≥100 tumour cells) and supernatant cfDNA for broad-panel NGS. Pleural fluid NGS has >90% concordance with tissue NGS. This is a Category 1 NCCN 2026 recommendation.
NSCLC TNM Staging — 9th Edition (IASLC)
The IASLC 9th Edition TNM Classification (published 2024/2025, implemented 2026) per NCCN v5.2026 and ESMO 2025/2026.
T — Primary Tumour
| T Category | Definition |
|---|---|
| TX | Primary tumour cannot be assessed, or proven by malignant cells in sputum/washings but not visualised by imaging or bronchoscopy |
| T0 | No evidence of primary tumour |
| Tis | Carcinoma in situ (Squamous or Adenocarcinoma) |
| T1mi | Minimally invasive adenocarcinoma |
| T1a | Tumour ≤1 cm |
| T1b | Tumour >1 cm but ≤2 cm |
| T1c | Tumour >2 cm but ≤3 cm |
| T2 | Tumour >3 cm but ≤5 cm; OR involves main bronchus (not carina), invades visceral pleura, or associated with atelectasis/obstructive pneumonitis |
| T2a | Tumour >3 cm but ≤4 cm |
| T2b | Tumour >4 cm but ≤5 cm |
| T3 | Tumour >5 cm but ≤7 cm; OR directly invades parietal pleura, chest wall, phrenic nerve, parietal pericardium; OR separate tumour nodules in the same lobe |
| T4 | Tumour >7 cm; OR invades mediastinum, heart, great vessels, trachea, recurrent laryngeal nerve, esophagus, vertebral body, carina; OR separate tumour nodules in a different ipsilateral lobe |
N — Regional Lymph Nodes
| N Category | Definition | 9th Edition Change |
|---|---|---|
| NX | Regional lymph nodes cannot be assessed | — |
| N0 | No regional lymph node metastasis | — |
| N1 | Metastasis in ipsilateral peribronchial and/or ipsilateral hilar nodes and intrapulmonary nodes | — |
| N2a | Metastasis in a SINGLE ipsilateral mediastinal station | NEW in 9th Edition — T1N2a = Stage IIB (was IIIA in 8th Edition) |
| N2b | Metastasis in MULTIPLE ipsilateral mediastinal stations | NEW in 9th Edition — T2N2b = Stage IIIB |
| N3 | Metastasis in contralateral mediastinal, contralateral hilar, ipsilateral or contralateral scalene, or supraclavicular lymph nodes | — |
M — Distant Metastasis
| M Category | Definition | 9th Edition Change |
|---|---|---|
| M0 | No distant metastasis | — |
| M1a | Separate tumour nodule in contralateral lobe; tumour with pleural or pericardial nodules; malignant pleural/pericardial effusion | — |
| M1b | Single extrathoracic metastasis in a single organ (including single non-regional LN) | — |
| M1c1 | Multiple extrathoracic metastases in a SINGLE organ | NEW subdivision in 9th Edition |
| M1c2 | Multiple extrathoracic metastases in MULTIPLE organs | NEW — both M1c1 and M1c2 are Stage IVB; M1c2 carries significantly worse prognosis |
Key 9th Edition Stage Grouping Changes
| Stage | 9th Edition | vs 8th Edition |
|---|---|---|
| IIA | T1N1 | Downstaged from IIB |
| IIB | T1N2a (single-station N2) | Downstaged from IIIA |
| IIIA | T3N2a (single-station N2) | Reclassified |
| IIIB | T2N2b (multi-station N2) | Reclassified |
| IVB | M1c1 (single organ) and M1c2 (multi-organ) | New M1c subdivision; M1c2 = worst prognosis |
Key Trial Data (2026)
| Trial | Setting | Regimen | Key Outcome |
|---|---|---|---|
| ADAURA | Adjuvant — EGFR-mutated (ex19del/L858R) Stage IB–IIIA | Adjuvant Osimertinib | Significant OS benefit: HR 0.49 (2023/2024 update) |
| ALINA | Adjuvant — ALK-positive Stage IB–IIIA | Adjuvant Alectinib × 2 years | Superior DFS vs platinum-based chemotherapy: HR 0.24 |
| CheckMate 816 | Neoadjuvant — Stage IB–IIIA | Nivolumab + platinum-doublet chemotherapy × 3 cycles → surgery | pCR 24% vs 2%; improved EFS. Benefit across all PD-L1 subgroups |
| CheckMate 77T / KEYNOTE-671 | Perioperative — Stage II–IIIA | Neoadjuvant chemo-IO → surgery → adjuvant IO (sandwich approach) | Significant EFS and OS improvement (KEYNOTE-671) vs chemo alone |
| FLAURA2 | 1L metastatic — EGFR-mutated | Osimertinib + Carboplatin/Pemetrexed | PFS 25 months vs 17 months (osimertinib monotherapy); higher toxicity |
| MARIPOSA | 1L metastatic — EGFR-mutated | Amivantamab + Lazertinib vs Osimertinib | PFS benefit: HR 0.70; higher toxicity (VTE, rash) |
| PAPILLON | 1L metastatic — EGFR exon 20 insertion | Amivantamab + Carboplatin/Pemetrexed | New standard of care: PFS 11.4 vs 6.7 months |
Viva Cases — Staging
Case 1: The Small N2 Node
Answer:
62-year-old, 2.5 cm upper lobe mass, single 1.2 cm station 4R LN positive on EBUS, no distant spread. Per 9th Edition: T1cN2a = Stage IIB (was IIIA in 8th edition). MDT discussion for upfront surgery + adjuvant therapy or neoadjuvant chemo-IO (CheckMate 816 or 77T).
Case 2: Multi-station N2
Answer:
3.5 cm tumour, biopsy-proven involvement of stations 4R and 7 (N2b). Stage: T2aN2b = Stage IIIB. If resectable: neoadjuvant chemo-IO preferred. If unresectable: definitive concurrent chemoradiation → 1 year durvalumab (PACIFIC protocol).
Case 3: Adjuvant Molecular Selection — ALK+
Answer:
4.5 cm resected adenocarcinoma (T2bN0M0, Stage IIA), ALK rearrangement found. Per ALINA trial: recommend adjuvant alectinib × 2 years. DFS benefit over platinum-based chemotherapy: HR 0.24.
Case 4: The M1c Subdivision
Answer:
Multiple liver metastases AND multiple bone metastases. Classification: M1c2 (multiple organs) = Stage IVB. This 9th Edition distinction reflects worse prognosis vs M1c1 (multiple lesions in one organ). First-line treatment depends on PD-L1 and molecular drivers.
Case 5: Neoadjuvant — Stage IIIA Squamous
Answer:
T4N0 squamous cell carcinoma, Stage IIIA. Current standard: neoadjuvant Nivolumab + platinum-doublet × 3 cycles → surgery (CheckMate 816). pCR correlates with improved EFS and OS.
Case 6: T3 Descriptors — 6 cm invading parietal pleura, N0
Answer:
T3N0 = Stage IIB. A tumour >5 cm but ≤7 cm OR invasion of parietal pleura (without chest wall) = T3. No nodes involved, no distant metastasis.
Malignant Pleural Effusion (MPE)
Based on ESMO 2025/2026 Living Guidelines, NCCN NSCLC V3.2026, and recent clinical trial data. MPE designates Stage 4 disease (M1a) in lung cancer. Management has shifted from hospital-based pleurodesis to patient-centred outpatient care.
Core Principles
- Primary goal: Symptom palliation (dyspnoea) — not radiographic resolution
- Initial approach: Diagnostic and therapeutic thoracentesis to assess symptom relief and lung re-expandability
- Management determinants: Patient choice, performance status (PS), and lung re-expandability
Diagnostic Workup
- Cytology: initial thoracentesis ~60% sensitivity; second thoracentesis adds ~15% yield
- Medical pleuroscopy (thoracoscopy): gold standard if cytology negative (sensitivity >90%)
- NCCN V3.2026: sufficient tissue for molecular testing (EGFR, ALK, ROS1, BRAF, PD-L1) — cell blocks often sufficient but biopsy preferred for comprehensive NGS
Treatment Selection Algorithm
Expandable Lung
Choose between:
- Talc Slurry: Preferred if patient wants a one-off procedure and is fit for 3–5 days hospitalisation
- IPC (Indwelling Pleural Catheter): Preferred if patient wants to avoid hospitalisation or has limited life expectancy
- IPC + Talc Slurry (IPC-PLUS protocol): Best of both — outpatient with highest pleurodesis rate (43% vs 22% IPC alone)
Non-Expandable Lung (Trapped Lung)
- IPC is the therapy of choice
- Talc pleurodesis is strictly contraindicated — visceral and parietal pleura cannot appose
- Surgical decortication: rarely, only in Stage 4 patients with very long expected survival (e.g., driver-mutation positive, fit for major thoracic surgery)
Key Trial Data — MPE
| Trial | Key Finding |
|---|---|
| AMPLE-2 (2025 long-term FU) | Daily drainage via IPC → 44% spontaneous pleurodesis rate vs 24% with symptom-guided drainage |
| AMPLE-3 (2025) | IPC + Talc may be superior to VATS surgical pleurodesis for reducing hospital days and repeat procedures; IPC-first strategies reduce total pleural-related hospital days by 3–5 |
| TUBE Trial | IPC insertion as outpatient significantly reduces initial hospital LOS vs talc slurry via chest tube |
| TACTIC Trial | Outpatient talc poudrage via IPC safe and effective; pleuroscopy-assisted IPC insertion with talc poudrage combines high diagnostic yield with rapid discharge |
| TIME2 Trial | No difference in dyspnoea relief between IPC and talc slurry; IPC requires fewer subsequent procedures and shorter hospital stays |
| TAPPS Trial | No significant difference in pleurodesis success at 90 days between talc poudrage (VATS) and talc slurry (bedside chest tube); slurry preferred unless VATS already planned for diagnosis |
| IPC-PLUS Trial | Talc slurry through IPC in outpatient setting: 43% pleurodesis rate vs 22% IPC alone |
Prognostication Tools
| Score | Variables | Risk Stratification |
|---|---|---|
| LENT Score | LDH in fluid, ECOG PS, Neutrophil-Lymphocyte Ratio (NLR), Tumour type | Low (0–1): median survival ~10 months | High (5–7): median survival ~1.5 months → prioritise IPC or simple drainage |
| PROMISE Score | Clinical variables + biological markers (haemoglobin, WBC, CRP) | Predicts 3-month mortality; guides intensity of intervention |
Trapped Lung
Pathophysiology: Dense fibrous layer (pleural rind) on the visceral pleura prevents lung expansion to meet parietal pleura during drainage. True "Trapped Lung" = chronic healed inflammatory process; "Lung Entrapment" in oncology = active tumour encasement or active pleural inflammation.
Diagnostic Markers
- Pneumothorax ex-vacuo on post-drainage CXR (not iatrogenic; air fills vacuum because lung cannot expand)
- Pleural manometry: Precipitous pressure drop >20 cmH₂O per litre drained
- Clinical: sharp pulling chest pain during drainage
Contraindicated
- Talc pleurodesis — strictly contraindicated (pleural surfaces cannot appose; will fail and may create locked-in infected space)
Treatment
- IPC = treatment of choice (symptom relief even without full lung expansion)
- Spontaneous pleurodesis via IPC in trapped lung: <5% — IPC usually permanent palliative tool
- Sub-analyses TIME2/AMPLE: 0% talc success rate in trapped lung
Pleurodesis — Agents & Technique
| Agent | Status | Notes |
|---|---|---|
| Talc (Sterile, Graded/Large-particle) | Gold standard | ~70–80% success rate; large-particle mandatory to minimise ARDS/systemic absorption risk |
| Bleomycin | Alternative | If talc unavailable or talc sensitivity; more expensive, generally less effective |
| Doxycycline / Silver Nitrate | Rarely used | Lower success rates and higher pain scores; not recommended by NCCN or ESMO 2026 |
Factors Predicting Success
- Lung expansion: Single most important predictor. Failure rate increases significantly if expansion <90% on post-drainage CXR
- Pleural fluid pH <7.3: Predicts lower pleurodesis success rate AND shorter life expectancy
- Low pleural glucose (<60 mg/dL): Higher tumour burden and lower success rates
Indwelling Pleural Catheter (IPC)
Core Indications (NCCN Category 1)
- Trapped lung — absolute gold standard
- Patient preference for outpatient management / avoid hospitalisation
- Poor performance status / limited life expectancy (high LENT score)
- Failed pleurodesis — salvage therapy
Drainage Protocol Evidence
- AMPLE-2: Daily drainage → 44% spontaneous pleurodesis vs 24% symptom-guided
- IPC-PLUS: Talc slurry via IPC outpatient → 43% pleurodesis vs 22% IPC alone
- Removal criteria: spontaneous pleurodesis = <50 mL drainage on three consecutive attempts + asymptomatic + expanded lung on imaging
Complication Management
| Complication | Rate | Management |
|---|---|---|
| Pleural infection | 2–5% | Do NOT remove IPC as first step; targeted antibiotics + aggressive drainage to clear space. Remove only if refractory to medical management |
| Fibrin blockage / loculations | Variable | Intrapleural fibrinolytics (tPA/DNase) via IPC — TIME3 sub-analysis supports safety. Restores drainage patency |
| Tract seeding | ~1% | Most common in mesothelioma. Managed with local radiotherapy; catheter removal usually not required |
Viva Cases — MPE / Pleural
Case 1: Initial Presentation — Large Symptomatic MPE
Answer:
65-year-old male with suspected NSCLC, large symptomatic right pleural effusion. First step: ultrasound-guided therapeutic and diagnostic thoracentesis — symptom relief, assessment of lung re-expansion, and cytological diagnosis including cell block for molecular markers.
Case 2: The Choice — Expandable Lung, ECOG 2, wants to stay home
Answer:
70-year-old, ECOG 2, lung re-expands fully. Recommendation: IPC. TIME2 and AMPLE trials show equivalent dyspnoea relief to talc slurry but with purely outpatient insertion and management.
Case 3: Trapped Lung — Is talc pleurodesis an option?
Answer:
No. Pleurodesis requires apposition of visceral and parietal pleura. In trapped lung this cannot occur. Proceed with IPC for long-term symptom management. Sub-analyses of TIME2/AMPLE show 0% talc success rate in trapped lung.
Case 4: IPC with Fever and Cloudy Drainage
Answer:
Likely pleural infection. Send fluid for culture; start broad-spectrum antibiotics; initiate regular drainage to clear the space. Do NOT remove the IPC as the first step — it provides necessary drainage. Remove only if infection fails to respond to treatment.
Case 5: EGFR-Mutated NSCLC with Moderate MPE — Pleurodesis immediately?
Answer:
Not necessarily. Per NCCN 2026, start 1st-line TKI therapy (e.g., osimertinib or lazertinib + amivantamab). In many cases, the MPE will resolve as systemic disease responds, potentially avoiding an invasive local procedure.
Case 6: Post-Drainage Pneumothorax ex-vacuo
Answer:
After draining 1.5 litres of MPE, post-procedure CXR shows large air space but no mediastinal shift. Patient still short of breath. This is pneumothorax ex-vacuo indicating trapped lung — the lung is unable to expand to fill the space previously occupied by fluid. Manage with IPC; talc is contraindicated.
Lung Cancer in the Context of ILD
Managing lung cancer with background interstitial lung disease (ILD) is one of the most challenging scenarios in oncology. As of 2026, background ILD is not just a comorbidity — it is a major independent risk factor for treatment-related mortality across all modalities.
Epidemiology & Risk Assessment
- Pre-existing ILD in ~5–10% of NSCLC patients; especially elderly male smokers
- UIP pattern (honeycombing, traction bronchiectasis) = highest risk of AE-ILD triggered by treatment
- Background ILD significantly decreases OS — from both cancer progression and respiratory failure
- Use Sato Risk Score (age, sex, CRP, CT pattern) to predict post-operative AE-ILD
Surgical Risks
- Risk of fatal AE-ILD after lung resection: 5–15%
- Prefer limited resections (segmentectomy/wedge) over lobectomy if oncologically feasible
- Multidisciplinary discussion mandatory for any patient with UIP pattern considering surgery
| Treatment Modality | Key Risks in ILD | 2026 Guidance |
|---|---|---|
| Surgery | Fatal AE-ILD post-resection: 5–15%; UIP pattern = highest risk | Prefer segmentectomy/wedge; use Sato Risk Score pre-operatively |
| Radiation (RT) | ILD patients have much lower threshold for severe RP; standard V20 limits unsafe | Target V20 <10–15% (vs standard 30–35%); minimise mean lung dose. SBRT: still 10% AE-ILD risk in fibrotic lungs |
| Chemotherapy | Gemcitabine, taxanes (docetaxel), vinorelbine can trigger AE-ILD; use with extreme caution | Prefer platinum + etoposide or pemetrexed; consider prophylactic nintedanib based on J-SONIC data (2025/2026) |
| EGFR-TKIs (Osimertinib) | ILD rate 3–4%; significantly higher with baseline lung fibrosis | Baseline HRCT mandatory; close monitoring (pulse oximetry, clinical review every 2 weeks for first 2 months); permanently discontinue for any grade ILD definitively attributed to TKI |
| Immunotherapy (ICI) | Excluded from almost all registration trials; real-world ILD/pneumonitis rate 20–30% in pre-existing ILD | Generally avoid in symptomatic or extensive fibrotic ILD. Mandatory MDT discussion for mild, stable ILD. HRCT every 6–9 weeks during treatment |
ILD and Pneumonitis — Grading & Management
Per CTCAE v6.0:
| Grade | Definition | Key Management Principle |
|---|---|---|
| Grade 1 — Asymptomatic | Radiographic changes only (GGOs), no clinical symptoms | Hold offending agent; monitor. Resume or dose-modify depending on drug class |
| Grade 2 — Symptomatic | New/worsening symptoms (dyspnoea, cough) not interfering with ADL | Hold agent; start prednisone 1–2 mg/kg; taper over ≥4–6 weeks minimum |
| Grade 3 — Severe | Severe symptoms, limiting self-care ADL, oxygen required | Permanently discontinue in most cases; IV methylprednisolone 2–4 mg/kg; hospitalise |
| Grade 4 — Life-threatening | Respiratory failure, intubation or mechanical ventilation | Permanently discontinue; maximal supportive care; escalate immunosuppression |
| Grade 5 | Death | — |
ADC-Induced ILD — Specific Protocols
Trastuzumab Deruxtecan (T-DXd) — DESTINY Trials
- Incidence: ~10–15% across DESTINY-Breast and DESTINY-Lung; most events within first 6–12 months
- Grade 1: Hold T-DXd; consider steroids if slow to resolve. If resolved to Grade 0 within 28 days, resume at same dose. If >28 days to resolve, reduce dose by one level
- Grade 2 or higher: PERMANENTLY DISCONTINUE T-DXd — even if patient recovers to Grade 0, do not re-challenge. This is a must-know exam point
Datopotamab Deruxtecan (Dato-DXd) — TROPION-Lung01
- Incidence: ~8% in TROPION-Lung01
- Similar to T-DXd: early intervention mandatory; Grade 2+ ILD = permanent cessation
- Stomatitis is the other major co-toxicity to manage alongside ILD monitoring
ICI Pneumonitis Management — NCCN 2026 / ESMO 2025
| Grade | Management | Re-challenge? |
|---|---|---|
| Grade 1 | Hold ICI; repeat CT in 2–4 weeks; if resolved, may resume ICI with close monitoring | Yes, with caution |
| Grade 2 | Hold ICI; prednisone 1–2 mg/kg; taper over ≥4–6 weeks. Do not stop steroids early (rebound risk) | Can consider once steroids <10 mg, but proceed with extreme caution |
| Grade 3–4 | Permanently discontinue ICI; hospitalise; IV methylprednisolone 2–4 mg/kg | No — permanently discontinue |
Steroid-Refractory Pneumonitis (no improvement at 48–72 hours)
- Infliximab 5 mg/kg (avoid if active infection or fungal risk)
- Mycophenolate Mofetil (MMF) 1 g twice daily
- IVIG or Cyclophosphamide in refractory cases
- Nintedanib increasingly used in 2026 guidelines as anti-fibrotic adjunct for persistent radiographic scarring
Viva Cases — ILD / Pneumonitis
Case 1: 70-year-old with NSCLC + subclinical UIP pattern — lobectomy?
Answer:
Very cautious approach. UIP pattern is a major risk factor for post-operative AE-ILD (5–15% risk of fatal event). Recommend MDT discussion to consider segmentectomy or SBRT instead of formal lobectomy to minimise surgical trauma to the fibrotic lung.
Case 2: PD-L1 80%, moderate IPF — pembrolizumab monotherapy?
Answer:
In most cases, no. Risk of Grade 5 pneumonitis in moderate IPF is prohibitive (up to 30% in some series). Discuss high risk of death from pneumonitis with patient; likely offer platinum-based chemotherapy instead. ICI only if ILD is very mild, stable, and after mandatory MDT discussion.
Case 3: Grade 2 ILD from T-DXd, fully resolved — can patient restart?
Answer:
No. Per current NCCN and FDA/EMA labels, T-DXd must be permanently discontinued for any Grade 2, 3, or 4 ILD. Re-challenge is associated with high risk of fatal recurrence. This applies even after complete resolution.
Case 4: ICI pneumonitis — much better after 1 week of prednisone, stop steroids?
Answer:
No. Steroids for pneumonitis must be tapered slowly over ≥4–6 weeks. Rapid tapers are associated with high rates of 'rebound' pneumonitis which can be more severe than the initial presentation.
Case 5: EGFR-mutant NSCLC + baseline interstitial changes — counsel on osimertinib?
Answer:
Baseline ILD increases risk of drug-induced pneumonitis on osimertinib (standard rate 3–4%, higher with baseline fibrosis). Baseline HRCT is mandatory. Monitor with pulse oximetry and clinical reviews every 2 weeks for first 2 months of therapy. Any TKI-attributed ILD → permanently discontinue osimertinib.
Case 6: Role of Nintedanib in NSCLC + IPF
Answer:
Based on recent data (extrapolated from J-SONIC trials 2025/2026), adding nintedanib to chemotherapy in patients with NSCLC and IPF may reduce the frequency of AE-ILD triggered by chemotherapy itself. This is a valid supportive strategy in 2026 for this high-risk population.
Calculators for This Page
Quantify screening risk and baseline performance status before your MDT discussion.
PLCOm2012: 11-variable model predicting 6-year lung cancer probability. Threshold ≥1.51% for screening eligibility. Validated in ILST and UK Lung Health Check programmes.
ECOG PS: Baseline performance status guides treatment intensity decisions across all lung cancer modalities.
Content reflects NCCN v2.2026, ESMO 2026 Living Guidelines, Fleischner Society 2026, Lung-RADS v2026, WHO 5th Edition, and IASLC 9th Edition TNM as of April 2026. For clinical decisions, always verify against the most current guideline version and individualise to patient context.