NCCN-IPI Calculator: Exact Scoring and Careful Interpretation
A source-backed guide to the five-factor NCCN-IPI for newly diagnosed diffuse large B-cell lymphoma in the rituximab era.
Use the calculator: Open the standalone NCCN-IPI calculator
What the NCCN-IPI measures
Zhou and colleagues developed the NCCN International Prognostic Index (NCCN-IPI) to improve prognostic discrimination for patients with newly diagnosed de novo diffuse large B-cell lymphoma treated in the rituximab era. The model retains five clinical domains while refining age and LDH and replacing a simple extranodal-site count with involvement of specified major organs.1
The score supports baseline prognostic stratification. It does not independently diagnose DLBCL, select treatment, or predict an individual patient's outcome.
Exact source-defined scoring
| Factor | Category | Points | | --- | --- | ---: | | Age | ≤40 years | 0 | | Age | 41-60 years | 1 | | Age | 61-75 years | 2 | | Age | >75 years | 3 | | LDH ratio to institutional ULN | ≤1 x ULN | 0 | | LDH ratio to institutional ULN | >1 through ≤3 x ULN | 1 | | LDH ratio to institutional ULN | >3 x ULN | 2 | | Ann Arbor stage | Stage III/IV | 1 | | ECOG performance status | ECOG ≥2 | 1 | | Major extranodal involvement | Bone marrow, CNS, liver/GI tract, or lung | 1 |
The LDH boundary deserves particular attention: exactly 1 x ULN scores 0; above 1 through 3 x ULN scores 1; and only values above 3 x ULN score 2. Use the ULN from the institution that measured the LDH rather than an absolute LDH value alone.
Total and risk groups
The five contributions sum to an exact total from 0 to 8.
| NCCN-IPI total | Risk group | Observed 5-year overall survival in the original development cohort | | ---: | --- | ---: | | 0-1 | Low | 96% | | 2-3 | Low-intermediate | 82% | | 4-5 | High-intermediate | 64% | | 6-8 | High | 33% |
These percentages are original development-cohort observations, not individualized prognoses. They summarize outcomes observed for groups in the source study and should not be presented as a precise forecast for one patient.
Interpretation safeguard: Document the five inputs, exact total, risk group, assessment date, and clinical context. Integrate the result with the complete diagnostic and clinical assessment; do not use the score alone as a treatment-selection rule.
Common calculation errors
- Treating the LDH 1-point band as including values below or equal to 1 x ULN.
- Placing exactly 3 x ULN in the 2-point band instead of the 1-point band.
- Counting any extranodal site rather than the specified bone marrow, CNS, liver/GI tract, or lung involvement.
- Calculating a favorable score when one or more factors are missing.
- Presenting the cohort survival observations as an individualized estimate.
Frequently asked questions
What exactly does the NCCN-IPI score?
It adds source-defined points for age, LDH ratio to the institutional upper limit of normal, Ann Arbor stage III/IV, ECOG performance status >=2, and involvement of bone marrow, CNS, liver/GI tract, or lung.
How is an LDH ratio of exactly 1 or exactly 3 scored?
A ratio at or below 1 x ULN scores 0. A ratio above 1 through 3 x ULN scores 1, so exactly 3 is in the 1-point band. A ratio above 3 x ULN scores 2.
Why are the survival percentages not individualized predictions?
The values are original development-cohort observations for groups of patients. They do not incorporate every patient-specific clinical, biologic, treatment, and follow-up factor.
Does the NCCN-IPI select treatment?
No. NCCN-IPI is a prognostic stratification model. Treatment decisions require the complete clinical assessment, pathology, staging, molecular findings, current guidance, and patient preferences.
What happens if one factor is missing?
The score should not be calculated. The OncoToolkit form requires one valid source-defined response for all five factors and returns Invalid Input for incomplete or malformed data.
Primary source
Zhou Z, Sehn LH, Rademaker AW, et al. An enhanced International Prognostic Index (NCCN-IPI) for patients with diffuse large B-cell lymphoma treated in the rituximab era. Blood. 2014;123(6):837-842. doi:10.1182/blood-2013-09-524108. Primary article.