{"entity":{"id":"male-breast-cancer","kind":"cancer","name":"Male breast cancer","aka":["Breast cancer in men"],"tldr":"Men get breast cancer too, usually a hormone-sensitive kind found as a lump near the nipple. It is treated much as in women, with surgery, radiotherapy and tamoxifen, and inherited BRCA2 mutations are found often enough that every man diagnosed is offered genetic testing. The main fix under way is including men in trials so their care stops being borrowed from women.","summary":"Male breast cancer is almost always invasive ductal carcinoma, oestrogen-receptor positive (in the large majority) and HER2-negative; lobular carcinoma is rare because men lack terminal lobules, and triple-negative disease is uncommon. Germline BRCA2 mutations are the strongest hereditary factor (BRCA1 less so), and testing is recommended for every man with breast cancer regardless of age or family history; other risks are Klinefelter syndrome, oestrogen exposure, radiation, obesity and liver disease. Men present later and with higher stage than women because there is no screening and awareness is low, and the tumour sits close to the skin and nipple.\n\nTreatment follows the female algorithm with adjustments. Mastectomy is usual because of tumour position, though breast-conserving surgery is feasible in some; sentinel node biopsy, radiotherapy and chemotherapy indications mirror women's. Endocrine therapy differs: tamoxifen is the preferred adjuvant agent, because aromatase inhibitors used alone in men raise testosterone and oestradiol through feedback and appear less effective, so if used they should be combined with a GnRH agonist. CDK4/6 inhibitors, HER2-directed therapy and PARP inhibitors for germline BRCA carriers are used in men on the basis of extrapolation and small cohorts. The EORTC 10085 / International Male Breast Cancer Program (Ann Oncol 2018) was the largest characterisation effort, and the FDA's 2020 guidance 'Male Breast Cancer: Developing Drugs for Treatment' instructs sponsors to include men in breast cancer trials rather than excluding them by default.\n\nOpen problems are adjuvant endocrine adherence and side effects in men, the biology of male-specific ER-positive disease, and the paucity of prospective data.","asOf":"2026-09-10","wikipedia":"https://en.wikipedia.org/wiki/Male_breast_cancer","links":[{"label":"NCI PDQ: male breast cancer","url":"https://www.cancer.gov/types/breast/male-breast-cancer"},{"label":"ASCO guideline: management of male breast cancer (JCO 2020)","url":"https://doi.org/10.1200/JCO.19.03120"},{"label":"FDA guidance: Male Breast Cancer, Developing Drugs for Treatment (2020)","url":"https://www.fda.gov/regulatory-information/search-fda-guidance-documents/male-breast-cancer-developing-drugs-treatment"},{"label":"International Male Breast Cancer Program (Ann Oncol 2018)","url":"https://doi.org/10.1093/annonc/mdx651"}],"tags":["nci-coverage","rare","breast"],"related":["breast-hr-positive","breast-her2-positive","tnbc","ductal-carcinoma-in-situ"],"cancers":[],"sections":[],"technologies":["endocrine-therapy","germline-testing","sentinel-node","parp-inhibitor","cdk46-inhibitor","mammography"],"targets":["estrogen-receptor","her2","brca","cdk4-6","parp"],"drugs":["tamoxifen","letrozole","fulvestrant","goserelin","palbociclib","ribociclib","abemaciclib","olaparib","talazoparib","trastuzumab"],"companies":[],"institutions":[],"pathways":["er-signaling","homologous-recombination-repair"],"terms":["hormone-receptor-status","mastectomy","gbrca-mutation","hereditary-cancer-syndromes"],"trials":["olympia","nct04842617"],"people":[],"bottlenecks":["b-trial-diversity","b-hereditary-risk","b-rare-cancers"],"keyPapers":["paper-cardoso-ann-oncol","paper-hassett-j-clin-oncol"],"journals":[],"dependsOn":[],"notes":[],"group":"breast","burden":"About one in a hundred breast cancers occurs in a man; the lifetime risk is roughly one in a thousand men, higher with a BRCA2 mutation, Klinefelter syndrome or a strong family history (SEER; NCI).","subtypes":["Invasive ductal carcinoma, ER-positive / HER2-negative (most)","HER2-positive (minority)","Triple-negative (rare)","Ductal carcinoma in situ (often papillary)","Hereditary (BRCA2, BRCA1, PALB2, CHEK2)"],"biomarkers":["ER, PR, HER2 (as in women)","Germline BRCA1/2 and multigene panel (recommended for all men with breast cancer)","Ki-67 and genomic assays (Oncotype DX validated mainly in women)","Nodal status","Testosterone and oestradiol if aromatase inhibitors are considered"],"standardOfCare":[{"setting":"Early stage","approach":"Mastectomy (or breast conservation where feasible) with sentinel node biopsy; adjuvant radiotherapy by the same criteria as women; chemotherapy and HER2-directed therapy as indicated.","refs":["mastectomy","sentinel-node","trastuzumab"],"guideline":{"nccn":"Category 2A","version":"NCCN Guidelines: Breast Cancer (special considerations for men); ASCO guideline on management of male breast cancer 2020","url":"https://doi.org/10.1200/JCO.19.03120"}},{"setting":"Adjuvant endocrine, ER-positive","approach":"Tamoxifen for five to ten years; aromatase inhibitor only with GnRH agonist suppression if tamoxifen is contraindicated.","refs":["tamoxifen","goserelin","letrozole"],"guideline":{"version":"ASCO 2020 male breast cancer guideline","url":"https://doi.org/10.1200/JCO.19.03120"}},{"setting":"Advanced, ER-positive","approach":"Endocrine therapy (tamoxifen, or aromatase inhibitor or fulvestrant with GnRH agonist) with a CDK4/6 inhibitor by extrapolation; chemotherapy for visceral crisis.","refs":["tamoxifen","fulvestrant","palbociclib","ribociclib","abemaciclib"],"guideline":{"version":"NCCN Guidelines: Breast Cancer"}},{"setting":"Germline BRCA carriers","approach":"PARP inhibitor (olaparib adjuvant per OlympiA; olaparib or talazoparib for metastatic disease) and cascade testing of relatives.","refs":["olaparib","talazoparib","germline-testing","olympia"]}],"stateOfArt":["Guidelines (ASCO 2020, NCCN) now state explicitly how to treat men rather than leaving it to inference from women's trials.","Universal germline testing in men with breast cancer finds BRCA2 mutations often and opens PARP inhibitor therapy and family cascade testing.","The FDA's 2020 guidance pushes sponsors to include men in breast cancer trials; labels for CDK4/6 inhibitors and other agents increasingly cover men.","The International Male Breast Cancer Program built the first large prospective registry, showing high ER positivity, low HER2 rates and under-treatment with adjuvant endocrine therapy."],"history":[{"year":1927,"title":"First large series of male breast cancer","note":"Wainwright's review of published cases.","refs":[]},{"year":1976,"title":"Tamoxifen shown active in men","note":"Early case series establish tamoxifen as the endocrine backbone.","refs":["tamoxifen"]},{"year":1995,"title":"BRCA2 linked to male breast cancer","note":"Wooster and colleagues identify BRCA2; male breast cancer is one of its hallmark phenotypes.","refs":["brca"]},{"year":2018,"title":"International Male Breast Cancer Program (EORTC 10085)","note":"Cardoso and colleagues (Ann Oncol 2018) characterise 1,483 men treated 1990 to 2010.","refs":[]},{"year":2020,"title":"ASCO guideline and FDA guidance","note":"First ASCO guideline on male breast cancer; FDA guidance on including men in breast cancer drug development.","refs":[]},{"year":2021,"title":"OlympiA: adjuvant olaparib for germline BRCA carriers","note":"Trial included men.","refs":["olaparib","olympia"]}],"pipeline":["olaparib","palbociclib","ribociclib","trastuzumab-deruxtecan"],"openProblems":["Men are still under-enrolled in breast cancer trials; regulatory guidance and label harmonisation are the response.","Aromatase inhibitor efficacy and the need for GnRH co-treatment rest on small studies; registries are collecting outcomes.","Later diagnosis from low awareness; education campaigns and rapid referral pathways are the levers.","Adjuvant endocrine adherence and side effects in men are poorly studied."],"parent":"breast-cancer"},"route":"/cancers/male-breast-cancer/","neighbours":{"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":"phyllodes-tumour","kind":"cancer","name":"Phyllodes tumour of the breast","route":"/cancers/phyllodes-tumour/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"technology":[{"id":"cdk46-inhibitor","kind":"technology","name":"CDK4/6 inhibitors","route":"/technologies/cdk46-inhibitor/"},{"id":"endocrine-therapy","kind":"technology","name":"Endocrine therapy (SERMs, AIs, SERDs)","route":"/technologies/endocrine-therapy/"},{"id":"germline-testing","kind":"technology","name":"Germline (hereditary) testing","route":"/technologies/germline-testing/"},{"id":"mammography","kind":"technology","name":"Mammography & tomosynthesis","route":"/technologies/mammography/"},{"id":"parp-inhibitor","kind":"technology","name":"PARP inhibitors","route":"/technologies/parp-inhibitor/"},{"id":"sentinel-node","kind":"technology","name":"Sentinel lymph node biopsy","route":"/technologies/sentinel-node/"}],"target":[{"id":"brca","kind":"target","name":"BRCA1 / BRCA2 (HRD)","route":"/targets/brca/"},{"id":"cdk4-6","kind":"target","name":"CDK4/6","route":"/targets/cdk4-6/"},{"id":"estrogen-receptor","kind":"target","name":"Estrogen receptor (ERα)","route":"/targets/estrogen-receptor/"},{"id":"her2","kind":"target","name":"HER2","route":"/targets/her2/"},{"id":"parp","kind":"target","name":"PARP","route":"/targets/parp/"}],"drug":[{"id":"abemaciclib","kind":"drug","name":"Abemaciclib","route":"/drugs/abemaciclib/"},{"id":"fulvestrant","kind":"drug","name":"Fulvestrant","route":"/drugs/fulvestrant/"},{"id":"goserelin","kind":"drug","name":"Goserelin / leuprolide (ovarian function suppression)","route":"/drugs/goserelin/"},{"id":"letrozole","kind":"drug","name":"Letrozole (and other aromatase inhibitors)","route":"/drugs/letrozole/"},{"id":"olaparib","kind":"drug","name":"Olaparib","route":"/drugs/olaparib/"},{"id":"palbociclib","kind":"drug","name":"Palbociclib","route":"/drugs/palbociclib/"},{"id":"ribociclib","kind":"drug","name":"Ribociclib","route":"/drugs/ribociclib/"},{"id":"talazoparib","kind":"drug","name":"Talazoparib","route":"/drugs/talazoparib/"},{"id":"tamoxifen","kind":"drug","name":"Tamoxifen","route":"/drugs/tamoxifen/"},{"id":"trastuzumab","kind":"drug","name":"Trastuzumab","route":"/drugs/trastuzumab/"},{"id":"trastuzumab-deruxtecan","kind":"drug","name":"Trastuzumab deruxtecan","route":"/drugs/trastuzumab-deruxtecan/"}],"pathway":[{"id":"homologous-recombination-repair","kind":"pathway","name":"Double-strand break repair: HR versus end joining","route":"/pathways/homologous-recombination-repair/"},{"id":"er-signaling","kind":"pathway","name":"Oestrogen receptor signalling","route":"/pathways/er-signaling/"}],"term":[{"id":"bia-alcl","kind":"term","name":"Breast implant-associated anaplastic large cell lymphoma","route":"/terms/bia-alcl/"},{"id":"terminal-duct-lobular-unit","kind":"term","name":"Ducts, lobules and the terminal duct lobular unit","route":"/terms/terminal-duct-lobular-unit/"},{"id":"gbrca-mutation","kind":"term","name":"Germline BRCA mutation (gBRCA)","route":"/terms/gbrca-mutation/"},{"id":"hereditary-cancer-syndromes","kind":"term","name":"Hereditary cancer syndromes","route":"/terms/hereditary-cancer-syndromes/"},{"id":"hormone-receptor-status","kind":"term","name":"Hormone receptor status (ER / PR)","route":"/terms/hormone-receptor-status/"},{"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)","route":"/terms/er-pr-scoring-breast/"},{"id":"mastectomy","kind":"term","name":"Mastectomy","route":"/terms/mastectomy/"},{"id":"nottingham-prognostic-index","kind":"term","name":"Nottingham Prognostic Index (NPI), and PREDICT","route":"/terms/nottingham-prognostic-index/"}],"trial":[{"id":"nct00261313","kind":"trial","name":"ACCELERATE: Doxorubicin and Cyclophosphamide Followed by Paclitaxel With Pegfilgrastim and Darbepoetin Alfa Support for the Treatment of Women With Breast Cancer","route":"/trials/nct00261313/"},{"id":"nct03711877","kind":"trial","name":"Comparative Study of Scalp Cooling System and Chemical Cold Cap (COHAIR Study)","route":"/trials/nct03711877/"},{"id":"nct03252431","kind":"trial","name":"Neulasta-controlled Trial of F-627 in Women With Breast Cancer Receiving Myelotoxic Chemotherapy","route":"/trials/nct03252431/"},{"id":"olympia","kind":"trial","name":"OlympiA","route":"/trials/olympia/"},{"id":"nct04842617","kind":"trial","name":"Phase III Study ：SHR6390/Placebo Combined With Endocrine Therapy for the Adjuvant Treatment of Hormone Receptor Positive,Human Epidermal Receptor 2 Ne","route":"/trials/nct04842617/"},{"id":"nct02872103","kind":"trial","name":"Placebo-controlled Trial of F-627 in Women With Breast Cancer Receiving Myelotoxic Chemotherapy","route":"/trials/nct02872103/"}],"bottleneck":[{"id":"b-hereditary-risk","kind":"bottleneck","name":"Inherited risk is mostly unidentified","route":"/bottlenecks/b-hereditary-risk/"},{"id":"b-rare-cancers","kind":"bottleneck","name":"Rare and paediatric cancers without markets","route":"/bottlenecks/b-rare-cancers/"},{"id":"b-trial-diversity","kind":"bottleneck","name":"Trials do not represent the people who get cancer","route":"/bottlenecks/b-trial-diversity/"}],"paper":[{"id":"paper-cardoso-ann-oncol","kind":"paper","name":"Characterization of male breast cancer: results of the EORTC 10085/TBCRC/BIG/NABCG International Male Breast Cancer Program","route":"/key-papers/paper-cardoso-ann-oncol/"},{"id":"paper-hassett-j-clin-oncol","kind":"paper","name":"Management of Male Breast Cancer: ASCO Guideline","route":"/key-papers/paper-hassett-j-clin-oncol/"}],"journal":[{"id":"breast-cancer-jbcs","kind":"journal","name":"Breast cancer","route":"/journals/breast-cancer-jbcs/"},{"id":"breast-cancer-research","kind":"journal","name":"Breast cancer research","route":"/journals/breast-cancer-research/"},{"id":"breast-cancer-research-and-treatment","kind":"journal","name":"Breast cancer research and treatment","route":"/journals/breast-cancer-research-and-treatment/"},{"id":"clinical-breast-cancer","kind":"journal","name":"Clinical breast cancer","route":"/journals/clinical-breast-cancer/"},{"id":"the-breast","kind":"journal","name":"The Breast","route":"/journals/the-breast/"},{"id":"the-breast-journal","kind":"journal","name":"The breast journal","route":"/journals/the-breast-journal/"}]}}