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4 slides generated from the cancer page, with a quiz from the open benchmark and speaker notes that cite the sources. Arrow keys move between slides; Print gives one slide per page.
Apocrine breast cancers are made of large cells resembling sweat-gland cells. They lack oestrogen and progesterone receptors but carry the androgen receptor, so the triple-negative ones sit in the luminal androgen receptor group and are the tumours in which androgen-blocking drugs have been tried.
Apocrine carcinoma shows distinct morphology (abundant eosinophilic granular cytoplasm and prominent nucleoli) with a characteristic steroid receptor profile that is oestrogen and progesterone receptor negative and androgen receptor positive; strictly defined, apocrine carcinomas express either HER2 or EGFR, which with androgen receptor positivity makes them candidates for targeted therapies (Vranic 2013). In the 5th edition of the WHO classification the entity is discussed as carcinoma with apocrine differentiation, reflecting debate about how much apocrine morphology is needed (Cserni 2020). The transcriptionally defined molecular apocrine group, ESR1-negative and AR- and FOXA1-positive, was 67 percent HER2 3+ and 57 percent GCDFP15-positive by immunohistochemistry and clinically aggressive, and almost all (94 percent) carried the HER2 3+ or GCDFP15-positive signature that none of the basal-like controls did (Lehmann-Che 2013). The HER2-negative apocrine tumours are therefore the histological face of the luminal androgen receptor subtype, whose phase 2 trials of bicalutamide and enzalutamide are on that page; the HER2-positive ones are treated as HER2-positive breast cancer.
| Setting | Approach | Guideline |
|---|---|---|
| Triple-negative apocrine carcinoma | As for triple-negative disease of no special type; androgen receptor antagonists only within trials (clinical benefit rates 19 to 33 percent in phase 2). | not mapped |