{"entity":{"id":"er-pr-scoring-breast","kind":"term","name":"How ER and PR are scored on a breast report (Allred score, H score, and why PR is not a UK core item)","aka":["Allred score","Allred","quick score","H score","histochemical score","ER score","ER percentage","ER 90 percent","PR score","PgR score","hormone receptor score","ER intensity","nuclear staining"],"tldr":"The oestrogen receptor test counts stained nuclei under a microscope and reports a percentage with an intensity, sometimes summarised as an Allred score out of 8 or an H score out of 300. There is no single agreed scoring method, the result is close to all-or-nothing in practice, and progesterone receptor is not actually a mandatory item on a UK report.","summary":"Both receptors are measured by immunohistochemistry on the biopsy, and only nuclear staining in the invasive part of the tumour counts. The whole invasive component is assessed. The threshold for positive is 1 percent of tumour nuclei and oestrogen receptor staining of 1 to 10 percent is reported separately as ER low positive, which is a different question with its own page here (`er-pr-negative-threshold`). What this term is about is the number beside the word positive.\n\nThe UK dataset requires the report to give the percentage of positive invasive nuclei, either as an absolute figure or in bands of about 10 percent, together with the average intensity as weak, moderate or strong, or a score. It notes that there are several scoring systems and no internationally accepted one. The two in common use are the Allred or quick score, which adds a proportion score (0 for none, 1 for under 1 percent, 2 for 1 to 10, 3 for 11 to 33, 4 for 34 to 66, 5 for 67 to 100 percent) to an intensity score (0 to 3) for a maximum of 8, with 3 or more counting as positive; and the H score, which multiplies the percentage of weakly, moderately and strongly stained nuclei by 1, 2 and 3 and sums them for a figure from 0 to 300. Where the Allred score and the 1 percent rule disagree, the dataset is explicit that the 1 percent rule wins in both directions. If the tumour is negative or only weakly positive, the report should also say whether the internal control tissue stained, because a failed stain and a true negative look the same.\n\nTwo things about the numbers are worth knowing. The distribution is bimodal: with modern methods most carcinomas are either completely negative or convincingly positive with more than 70 percent of nuclei stained, and only a few percent fall between, which is why a result of 90 percent and a result of 100 percent mean the same thing in practice while a result of 5 percent is a genuinely different animal. And progesterone receptor occupies a contested place. ASCO and CAP note that randomised adjuvant trials found no difference in the degree of benefit from endocrine treatment by PR status and that 'only ER should be used as a predictor of benefit from adjuvant endocrine therapy'; the RCPath writing group debated whether to include PR at all and, finding no consensus, did not make it a mandatory item of the UK dataset, while recommending it as good practice. NICE NG101 recommendation 1.3.3 does ask for it on every invasive cancer. PR earns its place as prognostic information within oestrogen receptor-positive disease, and as a quality control signal: an oestrogen receptor-negative, progesterone receptor-positive result is at best very rare and should prompt a review of the oestrogen receptor stain rather than a change of treatment. Finally, the dataset warns that the ER, PR and HER2 scores some multigene assays report are not to be used for clinical decisions; a disagreement with the immunohistochemistry is a reason to investigate the laboratory, not to re-route the patient.","asOf":"2026-09-25","links":[{"label":"Royal College of Pathologists G148: dataset for histopathological reporting of breast disease in surgical excision specimens of breast cancer, version 3, November 2024 (full review due November 2026)","url":"https://www.rcpath.org/resourceLibrary/g148-dataset-for-histopathological-reporting-of-breast-disease-in-surgical-excision-specimens-of-breast-cancer.html"},{"label":"Allison et al., Journal of Clinical Oncology 2020;38:1346 to 1366: oestrogen and progesterone receptor testing in breast cancer, ASCO/CAP guideline update","url":"https://doi.org/10.1200/jco.19.02309"},{"label":"NICE NG101: early and locally advanced breast cancer, diagnosis and management (published 18 July 2018, last updated 14 April 2025)","url":"https://www.nice.org.uk/guidance/ng101/chapter/recommendations"}],"tags":[],"related":["hormone-receptor-status","ihc","endocrine-therapy","er-pr-negative-threshold"],"cancers":["breast-cancer","breast-hr-positive","tnbc","ductal-carcinoma-in-situ","male-breast-cancer"],"sections":["diagnostics","hormonal"],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["er-pr-negative-threshold","hormone-receptor-status","grade-stage-receptor-breast","her2-testing-uk-breast","receptor-conversion-breast","ihc"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Ductal carcinoma in situ is scored differently, or not at all. Assessing oestrogen receptor status in DCIS without an invasive component is not a mandatory item of the UK dataset, there is no consensus on a cut-off, and the recommendation is to use the same method and threshold as for invasive cancer if it is measured at all, which it is when endocrine treatment is being considered. There are no data supporting progesterone receptor in DCIS."],"category":"Biomarkers"},"route":"/terms/er-pr-scoring-breast/","neighbours":{"term":[{"id":"er-pr-negative-threshold","kind":"term","name":"ER and PR negative under 1 percent (the triple-negative threshold, and ER-low)","route":"/terms/er-pr-negative-threshold/"},{"id":"grade-stage-receptor-breast","kind":"term","name":"Grade, stage and receptor status: three different things on one breast report","route":"/terms/grade-stage-receptor-breast/"},{"id":"her2-testing-uk-breast","kind":"term","name":"HER2 testing in the UK: reflex ISH, the ratio against the copy number, and where the UK differs from ASCO/CAP","route":"/terms/her2-testing-uk-breast/"},{"id":"hormone-receptor-status","kind":"term","name":"Hormone receptor status (ER / PR)","route":"/terms/hormone-receptor-status/"},{"id":"ihc","kind":"term","name":"Immunohistochemistry (IHC)","route":"/terms/ihc/"},{"id":"receptor-conversion-breast","kind":"term","name":"Receptor conversion: when the receptors change between the primary and a recurrence","route":"/terms/receptor-conversion-breast/"}],"technology":[{"id":"endocrine-therapy","kind":"technology","name":"Endocrine therapy (SERMs, AIs, SERDs)","route":"/technologies/endocrine-therapy/"}],"cancer":[{"id":"breast-cancer","kind":"cancer","name":"Breast cancer (all types)","route":"/cancers/breast-cancer/"},{"id":"ductal-carcinoma-in-situ","kind":"cancer","name":"Ductal carcinoma in situ (DCIS)","route":"/cancers/ductal-carcinoma-in-situ/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"male-breast-cancer","kind":"cancer","name":"Male breast cancer","route":"/cancers/male-breast-cancer/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"},{"id":"hormonal","kind":"section","name":"Hormonal Therapy","route":"/fronts/hormonal/"}]}}