{"entity":{"id":"tnm-breast-cancer-editions","kind":"term","name":"Which staging edition a breast report uses: UICC TNM 8, TNM 9 and the AJCC prognostic stage","aka":["TNM 8 breast","TNM 9 breast","UICC TNM breast","AJCC TNM breast","AJCC 8th edition breast","breast cancer staging edition","ypT","ypN","yp classification","TNM edition","Tis (DCIS)","Tis (LCIS)","T4d"],"tldr":"UK breast reports stage against the UICC's 8th edition, and the dataset warns against using the American AJCC 8th instead, because the two differ. The 9th edition, in force from January 2026, leaves breast staging alone; the one thing it changes is how a tumour is staged after chemotherapy given before surgery.","summary":"Three staging systems get quoted at a breast cancer patient and they are not interchangeable. The UICC TNM classification is the one UK reports use: the Royal College of Pathologists dataset in force names the eighth edition, reprints it as its appendix D, says it should be used for all tumours diagnosed after 1 January 2018, and warns in terms that 'it is recommended to use UICC TNM 8 (not AJCC TNM 8) as there are significant differences between the two staging systems'. The American Joint Committee on Cancer's eighth edition keeps the same anatomical categories but adds a prognostic stage that folds grade, oestrogen and progesterone receptor status, HER2 status and, for some hormone receptor-positive tumours, a genomic assay score into the stage group, which moves a large minority of patients up or down a stage; that system has its own page here (`ajcc-prognostic-stage-breast`) and UK clinicians do not usually quote it. NICE NG101 names no TNM edition and no AJCC prognostic stage anywhere in its recommendations, so a British treatment decision is not stranded by the difference.\n\nThe ninth edition of UICC TNM was published on 3 July 2025 and UICC recommends it take effect from 1 January 2026. For breast, in the committee's own words, 'the classification remains unchanged': the T, N and M categories and the stage groupings are the same as the eighth edition's. One thing was clarified, and it is the thing that matters most to anyone who has chemotherapy before surgery. The post-treatment y-pathological classification is now spelled out: ypT and ypN correspond to pT and pN, the ypT category 'must be based on the largest continuous focus of residual invasive cancer', not including treatment-related fibrosis, multiple residual foci are classified with the m suffix, and the report is recommended to add an estimate of the extent of residual disease by the residual cancer burden method (Brierley 2026). In other words, a 30 mm area of scar tissue with three 4 mm nests of cancer in it is ypT1a, not ypT2, and the residual cancer burden is what carries the rest of the information.\n\nTwo details of the eighth edition catch readers out and survive unchanged into the ninth. In situ disease is staged Tis with the type in brackets, Tis (DCIS), Tis (LCIS) or Tis (Paget's) for Paget disease of the nipple with no underlying carcinoma, so stage 0 on a letter means in situ disease. And T4d is not a size at all: it is inflammatory carcinoma, a clinical diagnosis, which is why an inflammatory breast cancer is stage III or IV from the day it is named however small the tumour turns out to be.","asOf":"2026-09-25","wikipedia":"https://en.wikipedia.org/wiki/Breast_cancer_classification","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":"Brierley et al., International Journal of Cancer 2026: the 9th edition of the UICC TNM classification of malignant tumours, updates and rationale for change (breast: the classification remains unchanged, the yp classification is clarified)","url":"https://doi.org/10.1002/ijc.70561"},{"label":"UICC: TNM Classification of Malignant Tumours, 9th edition, recommended to take effect from 1 January 2026","url":"https://www.uicc.org/what-we-do/sharing-knowledge/tnm"},{"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":["tnm-staging","cancer-stage","ajcc-stage","stage-shift","rcb"],"cancers":["breast-cancer","ductal-carcinoma-in-situ","lobular-carcinoma-in-situ","inflammatory-breast-cancer","paget-disease-of-the-nipple","tnbc"],"sections":["diagnostics"],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["grade-stage-receptor-breast","ajcc-prognostic-stage-breast","nottingham-prognostic-index","breast-tumour-size-on-the-report","rcb","pcr","carcinoma-in-situ"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Pathology"},"route":"/terms/tnm-breast-cancer-editions/","neighbours":{"term":[{"id":"ajcc-prognostic-stage-breast","kind":"term","name":"AJCC 8th edition prognostic stage for breast cancer","route":"/terms/ajcc-prognostic-stage-breast/"},{"id":"ajcc-stage","kind":"term","name":"AJCC stage (TNM staging manual)","route":"/terms/ajcc-stage/"},{"id":"carcinoma-in-situ","kind":"term","name":"Carcinoma in situ (CIS)","route":"/terms/carcinoma-in-situ/"},{"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":"nottingham-prognostic-index","kind":"term","name":"Nottingham Prognostic Index (NPI), and PREDICT","route":"/terms/nottingham-prognostic-index/"},{"id":"pcr","kind":"term","name":"Pathologic complete response (pCR)","route":"/terms/pcr/"},{"id":"rcb","kind":"term","name":"Residual cancer burden (RCB)","route":"/terms/rcb/"},{"id":"cancer-stage","kind":"term","name":"Stage","route":"/terms/cancer-stage/"},{"id":"stage-shift","kind":"term","name":"Stage shift","route":"/terms/stage-shift/"},{"id":"tnm-staging","kind":"term","name":"TNM staging","route":"/terms/tnm-staging/"},{"id":"breast-tumour-size-on-the-report","kind":"term","name":"Tumour size on a breast report, and why it differs from the scan","route":"/terms/breast-tumour-size-on-the-report/"}],"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-her2-positive","kind":"cancer","name":"HER2-positive breast cancer","route":"/cancers/breast-her2-positive/"},{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"inflammatory-breast-cancer","kind":"cancer","name":"Inflammatory breast cancer","route":"/cancers/inflammatory-breast-cancer/"},{"id":"lobular-carcinoma-in-situ","kind":"cancer","name":"Lobular carcinoma in situ (LCIS)","route":"/cancers/lobular-carcinoma-in-situ/"},{"id":"paget-disease-of-the-nipple","kind":"cancer","name":"Paget disease of the nipple","route":"/cancers/paget-disease-of-the-nipple/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"}]}}