# Apocrine carcinoma of the breast

Source: https://onco.cc/cancers/apocrine-carcinoma-breast/  
OnCo record `apocrine-carcinoma-breast` (Cancer). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

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.

## Summary

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.

## Fields

- Kind: Cancer
- Last checked: 2026-09-24
- Also known as: Carcinoma with apocrine differentiation; Apocrine breast cancer; Molecular apocrine carcinoma (overlapping expression subtype)
- Tags: breast; tnbc; subtype-page
- Group: breast
- Burden: A rare special type; the WHO classification counts carcinomas with apocrine differentiation among the special types and the molecular apocrine expression group overlaps the luminal androgen receptor subtype (Cserni 2020; Lehmann-Che 2013).
- Subtypes: HER2-negative apocrine carcinoma (triple-negative, luminal androgen receptor subtype); HER2-positive apocrine carcinoma (treated as HER2-positive breast cancer); Invasive carcinoma of no special type (ductal) with apocrine differentiation
- Biomarkers: ER and PR negative with androgen receptor positive; HER2 status (3+ in two thirds of molecular apocrine tumours); GCDFP15 (gross cystic disease fluid protein 15) and FOXA1 expression

## Sections of this record

The page is a hub with ten sections in reading order; large sections have their own page. The same plan as JSON: https://onco.cc/api/v1/cancers/apocrine-carcinoma-breast/sections.json

- Overview (on the hub): The TL;DR, the family this cancer belongs to, the organ, who gets it and what the state of the art is. https://onco.cc/cancers/apocrine-carcinoma-breast/#overview
- What it is (on the hub): Anatomy, the subtypes and how they differ, how it is staged, and where advanced disease spreads. https://onco.cc/cancers/apocrine-carcinoma-breast/#what-it-is [3 subtypes]
- Finding it (on the hub): How it shows itself, how it is confirmed, what screening exists, and the biomarkers clinicians test for. https://onco.cc/cancers/apocrine-carcinoma-breast/#finding-it [3 biomarkers]
- Treating it (on the hub): The standard of care by setting, the medicines, surgery and radiotherapy named in it, and the regimens behind them. https://onco.cc/cancers/apocrine-carcinoma-breast/#treating-it [1 setting, 1 decision with options]
- Evidence (on the hub): Trials recruiting now, the landmark trials, the key papers and what they mean, the latest literature, and the milestones year by year. https://onco.cc/cancers/apocrine-carcinoma-breast/#evidence
- The science (on the hub): The molecular landscape: the targets and how often each appears, the pathways, the mechanics stages and the preclinical models. https://onco.cc/cancers/apocrine-carcinoma-breast/#science [3 targets]
- Where you are (own page): Cases by country, the UK and NHS pathway and other country lenses, and the expert centres with trials on record. https://onco.cc/cancers/apocrine-carcinoma-breast/where-you-are/
- Living with it (on the hub): The decisions you may face, the aids that walk through them, the warnings on record, the first sixty days and the questions to ask. https://onco.cc/cancers/apocrine-carcinoma-breast/#living-with-it [8 questions, 2 red cards]
- What is coming (own page): Everything in development, the open problems and what is being done about them, the roadmaps, and what changed on this record. https://onco.cc/cancers/apocrine-carcinoma-breast/coming/ [2 medicines]
- Data (own page): Every connected record, the notes, the JSON, Markdown and RDF twins, and where the record came from and when it was checked. https://onco.cc/cancers/apocrine-carcinoma-breast/data/ [12 connected records]

## Standard of care

- 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). ([Bicalutamide](https://onco.cc/drugs/bicalutamide/), [Enzalutamide](https://onco.cc/drugs/enzalutamide/), [Androgen receptor](https://onco.cc/targets/androgen-receptor/))

## Sources

- Wikipedia: https://en.wikipedia.org/wiki/Breast_cancer_classification
- Vranic, Histol Histopathol 2013: apocrine carcinoma of the breast, a comprehensive review: https://doi.org/10.14670/hh-28.1393
- Lehmann-Che, Breast Cancer Res 2013: molecular apocrine breast cancers overexpress HER2 or GCDFP15: https://doi.org/10.1186/bcr3421
- Cserni, Pathologica 2020: histological type and typing of breast carcinomas and WHO classification changes: https://doi.org/10.32074/1591-951x-1-20
- Thomas, NPJ Breast Cancer 2023: rare subtypes of triple-negative breast cancer: https://doi.org/10.1038/s41523-023-00554-x

## Connected records

- cancers: [HER2-positive breast cancer](https://onco.cc/cancers/breast-her2-positive/), [Luminal androgen receptor triple-negative breast cancer (LAR)](https://onco.cc/cancers/tnbc-luminal-androgen-receptor/), [Triple-negative breast cancer (TNBC)](https://onco.cc/cancers/tnbc/)
- targets: [Androgen receptor](https://onco.cc/targets/androgen-receptor/), [EGFR](https://onco.cc/targets/egfr/), [HER2](https://onco.cc/targets/her2/)
- drugs: [Bicalutamide](https://onco.cc/drugs/bicalutamide/), [Enzalutamide](https://onco.cc/drugs/enzalutamide/)
- terms: [Androgen receptor-positive triple-negative breast cancer](https://onco.cc/terms/androgen-receptor-positive-tnbc/), [Luminal androgen receptor (LAR) subtype](https://onco.cc/terms/luminal-androgen-receptor/)

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JSON: https://onco.cc/api/v1/entities/apocrine-carcinoma-breast.json