{"entity":{"id":"basal-like","kind":"term","name":"Basal-like breast cancer","aka":["Basal-like subtype","Basal breast cancer","Basal-like intrinsic subtype","PAM50 basal-like","Basal-like carcinoma"],"tldr":"Basal-like is a breast cancer subtype defined by the genes its cells switch on, which resemble the basal cells lining the milk ducts. About four in five triple-negative cancers are basal-like and most basal-like cancers are triple-negative, but the two labels are not the same thing, and the overlap is where BRCA1-related cancers sit.","summary":"Perou and colleagues profiled 65 surgical specimens from 42 patients on cDNA microarrays of 8,102 genes and found the tumours could be classified into subtypes distinguished by pervasive differences in gene expression, the origin of the intrinsic subtypes luminal A, luminal B, HER2-enriched, basal-like and normal-like (Perou 2000). The Cancer Genome Atlas integrated copy number, methylation, exome, mRNA, microRNA and protein data across primary breast cancers, confirmed four main classes, found TP53, PIK3CA and GATA3 the only genes mutated in more than 10 percent overall, and showed basal-like tumours share many molecular features with high-grade serous ovarian cancer, implying a related aetiology and similar therapeutic opportunities (TCGA 2012). Triple-negative and basal-like overlap but are not identical: of 412 triple-negative tumours 21.4 percent were non-basal-like, and of 473 basal-like tumours 31.5 percent were not triple-negative; triple-negative tumours classified as luminal or HER2-enriched had expression profiles indistinguishable from their non-triple-negative counterparts, most HER2-enriched triple-negative tumours lacked HER2 amplification, and the authors suggest triple-negative trials stratify by basal-like versus non-basal-like expression (Prat 2013). In the population-based Carolina Breast Cancer Study, using immunohistochemical surrogates (ER, PR and HER2 negative with cytokeratin 5/6 or HER1 positive), basal-like tumours were found in 39 percent of premenopausal African American women against 14 percent of postmenopausal African American and 16 percent of non-African American women; they had more TP53 mutations (44 against 15 percent), higher mitotic index and grade, and among the shortest breast cancer-specific survival (Carey 2006). Basal-like cancers are the typical cancer of BRCA1 carriers, and adenoid cystic carcinoma is a special type of basal-like tumour with an excellent outlook (Ghabach 2010), a reminder that the label describes lineage, not behaviour. Within triple-negative disease Lehmann's basal-like 1 and 2 subtypes subdivide the group.","asOf":"2026-09-24","wikipedia":"https://en.wikipedia.org/wiki/Basal-like_carcinoma","links":[{"label":"Perou, Nature 2000: molecular portraits of human breast tumours","url":"https://doi.org/10.1038/35021093"},{"label":"Cancer Genome Atlas Network, Nature 2012: comprehensive molecular portraits of human breast tumours","url":"https://doi.org/10.1038/nature11412"},{"label":"Prat, Oncologist 2013: molecular characterisation of basal-like and non-basal-like triple-negative breast cancer","url":"https://doi.org/10.1634/theoncologist.2012-0397"},{"label":"Carey, JAMA 2006: race, breast cancer subtypes and survival in the Carolina Breast Cancer Study","url":"https://doi.org/10.1001/jama.295.21.2492"},{"label":"Ghabach, Breast Cancer Res 2010: adenoid cystic carcinoma of the breast in the United States 1977 to 2006 (SEER)","url":"https://doi.org/10.1186/bcr2613"}],"tags":["breast","tnbc"],"related":[],"cancers":["tnbc","tnbc-basal-like-1","tnbc-basal-like-2","brca-associated-tnbc","adenoid-cystic-carcinoma-breast","high-grade-serous-ovarian-cancer"],"sections":[],"technologies":[],"targets":["tp53","brca"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["claudin-low"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"category":"Cancer biology"},"route":"/terms/basal-like/","neighbours":{"cancer":[{"id":"adenoid-cystic-carcinoma-breast","kind":"cancer","name":"Adenoid cystic carcinoma of the breast","route":"/cancers/adenoid-cystic-carcinoma-breast/"},{"id":"tnbc-basal-like-1","kind":"cancer","name":"Basal-like 1 triple-negative breast cancer (BL1)","route":"/cancers/tnbc-basal-like-1/"},{"id":"tnbc-basal-like-2","kind":"cancer","name":"Basal-like 2 triple-negative breast cancer (BL2)","route":"/cancers/tnbc-basal-like-2/"},{"id":"brca-associated-tnbc","kind":"cancer","name":"BRCA-associated triple-negative breast cancer","route":"/cancers/brca-associated-tnbc/"},{"id":"medullary-pattern-breast-carcinoma","kind":"cancer","name":"Carcinoma with medullary pattern (medullary breast cancer)","route":"/cancers/medullary-pattern-breast-carcinoma/"},{"id":"high-grade-serous-ovarian-cancer","kind":"cancer","name":"High-grade serous ovarian cancer","route":"/cancers/high-grade-serous-ovarian-cancer/"},{"id":"tnbc-mesenchymal","kind":"cancer","name":"Mesenchymal triple-negative breast cancer (M)","route":"/cancers/tnbc-mesenchymal/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"target":[{"id":"brca","kind":"target","name":"BRCA1 / BRCA2 (HRD)","route":"/targets/brca/"},{"id":"tp53","kind":"target","name":"TP53","route":"/targets/tp53/"}],"term":[{"id":"claudin-low","kind":"term","name":"Claudin-low breast cancer","route":"/terms/claudin-low/"},{"id":"health-disparities","kind":"term","name":"Health disparities in cancer outcomes (ethnicity, deprivation and access)","route":"/terms/health-disparities/"},{"id":"luminal-androgen-receptor","kind":"term","name":"Luminal androgen receptor (LAR) subtype","route":"/terms/luminal-androgen-receptor/"}]}}