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Clinical calculator summary

Original 1998 Allred ER/PR IHC score

A two-component pathology score combining positive tumor-cell proportion and average nuclear staining intensity.

Evidence-based context for fast calculator use

Purpose:
Reproduce the original Allred score and classification for one ER or PR assay without making a treatment recommendation.
Population:
Pathologist-assessed nuclear ER or PR immunohistochemistry in breast carcinoma; ER and PR are scored separately.
Factors:
Positive tumor-cell proportion category, Average nuclear staining intensity, Coherent none/positive staining combination
Reference:
Allred et al. Mod Pathol. 1998;11(2):155-168. PMID:9504686.
HomeAllred Score for ER/PR
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Allred Score for ER/PR

Clinical Context & Background

This calculator reproduces the original 1998 Allred scoring system. For one receptor assay, it adds the source-defined positive tumor-cell proportion category (0-5 points) to average nuclear staining intensity (0-3 points). Coherent totals are 0 or 2-8; totals 0-2 are Allred negative and 3-8 are Allred positive.
Calculate ER and PR separately. The categories describe pathologist-assessed nuclear immunohistochemistry in breast carcinoma. This is not a HER2 scoring system or an automated image-analysis method. The historical Allred classification does not replace current receptor-reporting guidelines and is not an individualized prognosis, endocrine-treatment eligibility rule, expected-benefit estimate, or treatment recommendation.
Primary Source EvidenceAllred DC, Harvey JM, Berardo M, Clark GM. Prognostic and predictive factors in breast cancer by immunohistochemical analysis. Mod Pathol. 1998;11(2):155-168. PMID:9504686.
Formula Logic
Original 1998 Allred score = proportion score (0-5) + average staining-intensity score (0-3). Coherent totals are 0 or 2-8; 0-2 is Allred negative and 3-8 is Allred positive.

Reference Data

Total ScoreOriginal ClassificationScope
0 - 2Allred negativeHistorical ER or PR IHC classification
3 - 8Allred positiveHistorical ER or PR IHC classification

Clinical Workflow

Use, Interpret, And Continue The Patient Pathway

Expand for workflow guidance, limitations, examples, and related next steps.

When To Use

  • Use for pathologist-assessed nuclear ER or PR immunohistochemistry in breast carcinoma.
  • Complete a separate calculation for ER and for PR.

How To Interpret

  • Add the source-defined proportion and intensity contributions.
  • Original totals 0-2 are Allred negative and 3-8 are Allred positive; score 1 is not possible with coherent inputs.

What To Do Next

  • Report and interpret receptor findings under current pathology and clinical guidance.
  • Integrate the result with the complete pathology report and patient-specific clinical assessment.

Limitations

  • Not a HER2 score or automated image-analysis method.
  • Does not replace modern receptor-reporting guidelines.
  • Not an individualized prognosis, endocrine-treatment eligibility rule, benefit estimate, or treatment recommendation.

Validated Population

Breast carcinoma specimens assessed for nuclear ER or PR immunohistochemistry in the original Allred framework.

Calculation verification history

Verified

  1. : Production browser revalidation

    • Three source-backed Allred cases passed through visible production controls at score 0, the score-3 positive threshold, and the incoherent-input rejection path.
    • No unexpected N/A, literal undefined value, stale control, unsupported risk gauge, or browser-console error was observed.
    Download latest production check (Excel)

    Case-level evidence is retained in validation/browser-revalidation/allred-score-estrogen-progesterone-2026-08-03.json.

  2. : Production browser validation

    • Ten source-backed cases were exercised on the public production route through visible browser controls; 10/10 case records passed their expected-versus-observed assertions across 11 visible submissions.
    • Overall browser status: failed-console. medium: Production emitted minified React error #418 during the route load.
    • Case-level inputs, expected and observed results, reset/repeat behavior, failure reproductions, and console evidence are retained in the production-browser evidence record.

    Case-level production evidence is retained in validation/browser-production/allred-score-estrogen-progesterone.json.

  3. : Full validation test

    • 320/320 exhaustive source-category, score-boundary, strict-input, UI/reset, trace, wording, immutability, registry, and no-panel checks passed with zero score or classification mismatches.
    • Scope is the original 1998 pathologist-assessed nuclear IHC score, calculated separately for ER and PR; no panel calculates Allred or inherits this status.

  4. : Calculation and input-contract correction

    • Replaced favorable numeric defaults and Number coercion with two mandatory semantic categories, exact-key validation, and rejection of legacy points, malformed values, missing or extra fields.
    • Enforced coherent staining: none proportion requires none intensity, while every positive proportion requires non-none intensity; this prevents impossible score 1 and NaN-positive results.
    • Corrected proportion boundary labels and removed treatment-eligibility and expected-benefit claims; added separate ER/PR scope, two contributions, reconciled trace, and matched source row.

Verification confirms the calculator implementation against the cited model; it is not independent clinical validation, regulatory approval, or medical advice.

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Frequently Asked Questions

When should Allred Score for ER/PR be used?

Use it for patients undergoing breast cancer risk, staging, pathology, recurrence, or treatment-benefit assessment when all required inputs and the intended clinical setting are confirmed.

Can Allred Score for ER/PR determine treatment by itself?

No. Interpret the result with the cited evidence, complete clinical assessment, current guidelines, and patient-specific goals.

Evidence-based oncology decision support. Verify with clinical guidelines.