🎀 Oncology

Breast Cancer

Most common cancer in women — outcomes excellent when detected early through screening or symptom awareness.

Overview

Breast cancer affects roughly 1 in 7 women in the UK during their lifetime. It also occurs in men (under 1%). Most cancers arise in the ductal or lobular epithelium and are stratified by hormone receptor (ER/PR) and HER2 status, which drives treatment. Five-year survival is over 85% with stage 1–2 disease, falling sharply at stage 4.

Symptoms

  • New breast or axillary lump or thickening
  • Skin dimpling, puckering or peau d'orange
  • Nipple inversion, eczema-like change (Paget's), or bloody discharge
  • Change in size or contour of one breast
  • Persistent breast pain (less common as sole symptom)

Risk factors

  • Age >50, female sex
  • Family history (first-degree relative)
  • Dense breast tissue
  • Previous benign atypical hyperplasia or LCIS

Causes

  • Inherited mutations: BRCA1/2, PALB2, TP53, CHEK2 (~5–10% of cases)
  • Hormonal exposure: early menarche, late menopause, nulliparity, HRT
  • Lifestyle: alcohol, obesity, physical inactivity, postmenopausal weight gain
  • Prior chest radiotherapy (e.g. for Hodgkin lymphoma)

🚨 Red flags — seek urgent care

  • New unilateral lump or skin change at any age
  • Bloody nipple discharge
  • Axillary lymphadenopathy with breast symptoms
  • Inflammatory presentation: rapid redness/oedema (inflammatory breast cancer)

When to seek care

  • Any new persistent breast change — 2-week-wait suspected cancer referral if over 30
  • Any new lump under 30 — urgent imaging if other concerning features
  • Family history — refer to genetics if pattern suggestive

Diagnosis

  • Triple assessment: clinical exam + imaging (mammography ± ultrasound, MRI selectively) + core biopsy
  • Biopsy determines histology, grade, ER/PR/HER2 status, Ki-67
  • Staging: nodal ultrasound ± sentinel node biopsy; CT chest/abdo/pelvis and bone scan for high-risk or symptomatic
  • Genetic testing (BRCA panel) if eligibility criteria met

Treatment

  • Surgery: breast-conserving surgery + sentinel node biopsy, or mastectomy ± reconstruction
  • Radiotherapy after breast-conserving surgery and selected mastectomy cases
  • Endocrine therapy (tamoxifen, aromatase inhibitor) for ER-positive disease — 5–10 years
  • Chemotherapy (anthracycline/taxane) for higher-risk or triple-negative disease
  • HER2-targeted therapy (trastuzumab ± pertuzumab) for HER2-positive disease — 1 year
  • CDK4/6 inhibitors, PARP inhibitors (BRCA), immunotherapy in advanced/triple-negative settings

Prevention

  • Maintain healthy weight, limit alcohol to <14 units/week, regular exercise
  • Breastfeeding has modest protective effect
  • Attend NHS Breast Screening (50–71 every 3 years)
  • Risk-reducing surgery/medication (tamoxifen, anastrozole) for high genetic risk

Complications

  • Lymphoedema after axillary surgery/radiotherapy
  • Treatment-related cardiotoxicity (anthracyclines, trastuzumab, left-sided radiotherapy)
  • Premature menopause and reduced fertility
  • Recurrence (local, regional, distant — bone, liver, lung, brain)

Prognosis

5-year survival: ~98% stage 1, ~90% stage 2, ~70% stage 3, ~25% stage 4. Outcomes continue to improve with targeted therapies.

Education & self-care

Be 'breast aware': know what is normal for you, check monthly, and report any new change promptly. Most changes are not cancer — but early diagnosis dramatically improves outcomes.

Frequently asked questions

Does a lump always mean cancer?

No — most breast lumps are benign (cysts, fibroadenomas). Any new lump still warrants assessment.

Should I have a BRCA test?

Genetic testing is offered when family history meets NICE criteria or after a young-onset cancer diagnosis.

Is HRT safe after breast cancer?

Systemic HRT is generally avoided after ER-positive cancer. Discuss non-hormonal options for symptoms.

Medically reviewed by Dr. Handel Emery, MD, FRCP (UK) · Last reviewed 2026-06-08