AKT · Endocrine/Breast

Breast cancer

Malignancy of breast ductal/lobular epithelium

Overview

The commonest cancer in women. Usually a hard, irregular, fixed, painless lump ± nipple/skin change, detected by the patient or on screening (mammography, ages 50–70). Triple assessment (clinical + imaging + biopsy) confirms it; receptor status (ER/PR/HER2) guides treatment (surgery, radiotherapy, endocrine therapy, chemotherapy, anti-HER2).

Recognise

Hard, irregular, fixed, usually PAINLESS lump (often upper outer quadrant); skin tethering/dimpling, peau d'orange, nipple retraction/discharge
Axillary lymphadenopathy; risk factors: age, family history (BRCA1/2), oestrogen exposure (early menarche/late menopause, nulliparity, HRT), obesity
Inflammatory breast cancer: erythematous, oedematous, warm breast (mimics mastitis but no response to antibiotics)

Red flags

≥30 with an unexplained breast lump → suspected-cancer pathway (2-week-wait); ≥50 with unilateral nipple changes (discharge/retraction)
Inflammatory breast cancer mimicking 'mastitis' not settling on antibiotics → refer urgently
Strong family history/BRCA → genetics and surveillance

Differentials & how to tell them apart

Fibroadenomayoung woman, smooth, mobile ('breast mouse'), firm, painless — benign

Breast cystsmooth, fluctuant, may be tender; resolves on aspiration

Fat necrosisfirm lump after trauma/surgery — can mimic cancer; biopsy to confirm

Mastitis/abscessred, hot, tender, systemically unwell — but inflammatory cancer mimics it

Investigations

TRIPLE ASSESSMENT: clinical exam + imaging (mammography ± ultrasound; MRI in selected) + core biopsy (histology, ER/PR/HER2). Staging and sentinel-node assessment.

Management

Triple assessment → surgery + adjuvant therapy guided by receptor status

1Refer on the suspected-cancer pathway and perform triple assessment. Treatment is surgery (breast-conserving + radiotherapy, or mastectomy) with sentinel-node assessment, then adjuvant therapy guided by ER/PR/HER2 and risk.Gate: Receptor status drives systemic therapy: ER-positive → endocrine therapy (TAMOXIFEN if pre-menopausal — counsel VTE/endometrial cancer risk; AROMATASE INHIBITOR if post-menopausal); HER2-positive → trastuzumab; 'mastitis' not settling = exclude inflammatory cancer
2Adjuvant chemotherapy/radiotherapy per risk; neoadjuvant therapy for large/HER2 tumours; BRCA testing and risk-reducing options; lifelong follow-up.

Surgery (wide local excision or mastectomy) + sentinel node biopsy — primary treatment

Endocrine therapy (tamoxifen pre-menopausal; aromatase inhibitor post-menopausal) — for ER-positive disease; tamoxifen → VTE/endometrial cancer risk

Anti-HER2 (trastuzumab) / chemotherapy / radiotherapy — HER2-positive disease / adjuvant per risk

Key points

Hard fixed painless lump + skin/nipple change = cancer until triple assessment says otherwise. Know the 2-week-wait thresholds (≥30 lump; ≥50 nipple change) and the receptor-driven endocrine therapy (tamoxifen pre- / aromatase inhibitor post-menopausal). Inflammatory cancer masquerades as mastitis.

Monitor & prognosis

Surveillance imaging; endocrine-therapy adherence/side-effects.

Good if early; receptor-tailored therapy improves outcomes.

Source: NICE NG101; CKS Breast cancer recognition & referral