Clinical calculator summary
Original 1993 Mayo Clinic MACIS prognostic score
Clinical calculator summary
Original 1993 Mayo Clinic MACIS prognostic score
A postoperative equation using distant metastasis, age, completeness of resection, local invasion, and primary-tumor size.
Evidence-based context for fast calculator use
- Purpose:
- Reproduce the original MACIS score and its historical 20-year cause-specific-survival group without presenting an individualized prognosis.
- Population:
- Patients with papillary thyroid carcinoma after definitive surgery and pathological assessment in the original Mayo Clinic cohort.
- Factors:
- Completed-years age, Tumor size in cm, Completeness of resection, Local invasion, Distant metastasis
- Reference:
- Hay et al. Surgery. 1993;114(6):1050-1057. PMID: 8256208.
MACIS Score (Thyroid)
Clinical Context & Background
Age term = 3.1 when age <=39 years, otherwise 0.08 x age. Original 1993 MACIS = age term + 0.3 x tumor size (cm) + 1 if resection is incomplete + 1 if local invasion is present + 3 if distant metastasis is present.Reference Data
| Raw score | Historical 20-year cause-specific survival |
|---|---|
| <6 | 99% |
| 6-6.99 | 89% |
| 7-7.99 | 56% |
| >=8 | 24% |
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
Clinical Workflow
Use, Interpret, And Continue The Patient Pathway
Expand for workflow guidance, limitations, examples, and related next steps.
When To Use
- Use after definitive surgery and pathological assessment for papillary thyroid carcinoma.
- Enter completed-years age, maximum primary-tumor size in cm, and explicit postoperative resection, invasion, and metastasis findings.
How To Interpret
- The raw unrounded score selects one of four historical 20-year cause-specific-survival rows.
- Age 39 and younger uses the fixed 3.1 term; age 40 and older uses 0.08 multiplied by age.
What To Do Next
- Integrate the historical score with current staging, pathology, molecular findings, response-to-therapy assessment, comorbidity, patient goals, and specialist judgment.
- Do not choose treatment or surveillance from MACIS alone.
Limitations
- Historical outcomes came from patients treated from 1940 through 1989 and may not represent contemporary care.
- Not an individualized survival estimate, recurrence calculator, or treatment-selection rule.
- Not validated here for follicular, medullary, poorly differentiated, or anaplastic thyroid carcinoma.
- No unsupported maximum is imposed on age or tumor size.
Validated Population
Postoperative papillary thyroid carcinoma in the original Mayo Clinic cohort.
Exact score boundary
Age 40, tumor size 6 cm, incomplete resection, no local invasion, and no distant metastasis gives a raw MACIS score of exactly 6.00.
Calculation verification history
Verified
Calculation verification history
Verified: Production browser revalidation
- Three source-backed cases passed through visible production controls immediately below 6, at 6, and at 8.
- The former rounded-score contradiction was absent; the below-boundary result displayed <6.00.
- No unexpected N/A, literal undefined value, stale control, unsupported gauge, or browser-console error was observed.
Case-level evidence is retained in validation/browser-revalidation/macis-thyroid-cancer-score-2026-08-03.json.
: Boundary-safe score display corrected and browser-revalidated locally
- Cutoff-adjacent raw scores now use <6.00, <7.00, or <8.00 only when ordinary two-decimal rounding would otherwise cross the historical row's exclusive upper boundary; exact thresholds retain their ordinary display.
- The visible tumor-size field now enforces the existing strictly-positive source contract before calculation.
- Ten visible-browser cases passed across 11 submissions, covering the age-39/40 term transition, score boundaries, all adverse factors, invalid size, and reset/repeat; the independent audit remains 388/388.
Case-level local remediation evidence is retained in validation/browser-production/macis-thyroid-cancer-score.local-remediation.json; the original production finding remains retained separately.
: Production browser validation found rounded-boundary contradictions
- All ten raw calculations and input dispositions matched the original MACIS oracle across 11 visible Calculate attempts.
- Two UI cases failed: raw 5.9997 correctly remained in the below-6 row while displaying 6.00, and raw 6.9997 correctly remained in the 6-6.99 row while displaying 7.00.
- Age 39/40 logic, exact 6/7/8 boundaries, all adverse terms, invalid-size blocking, and reset/repeat otherwise passed; production also emitted React hydration error #418.
Case-level production evidence is retained in validation/browser-production/macis-thyroid-cancer-score.json.
: Browser input adapter corrected and reverified
- Accepted finite number values already normalized by the shared calculator form while retaining strict malformed-input rejection.
- No equation, cutoff, unit, classification, or applicability rule changed; calculator-specific verification and the calculator-wide browser-input audit passed.
: Full validation test
- 388/388 independent equation, exact-boundary, malformed-input, trace, historical-outcome, UI, reset, immutability, card, download, catalog, and no-panel-inheritance checks passed.
- No registered master panel calculates MACIS; no panel receives inherited MACIS verification.
: Calculation and input-contract correction
- Removed favorable defaults and unsafe coercion; all five exact inputs are required, age must be an integer >=0, tumor size must be finite and >0 cm, and categorical findings must use explicit source enums.
- Added raw unrounded score classification, a five-term contribution trace, matched historical outcome row, and wording limited to postoperative papillary thyroid carcinoma without individualized survival or treatment claims.
Verification confirms the calculator implementation against the cited model; it is not independent clinical validation, regulatory approval, or medical advice.
Related Tools
Frequently Asked Questions
How is age handled at 39 and 40 years?
Age 39 uses the fixed age term 3.1. Age 40 uses 0.08 x 40 = 3.2.
Is the displayed rounded score used for classification?
No. The historical outcome row is selected from the raw unrounded score. A boundary-safe less-than label is shown only when ordinary two-decimal rounding would otherwise cross the row’s exclusive upper cutoff.
Does MACIS provide an individualized survival estimate?
No. The percentages are historical cohort observations and must not be interpreted as personalized predictions or treatment recommendations.
Evidence-based oncology decision support. Verify with clinical guidelines.