Breast Cancer

Aetiology/Causes:

The development of breast cancer is multifactorial and may include:

• Genetic predisposition: Inherited mutations such as BRCA1 and BRCA2 significantly increase the risk.

• Hormonal factors: Estrogen and progesterone have a role in the growth of certain types of breast cancer.

• Family history: A strong family history of breast cancer, especially at a young age, increases risk.

• Lifestyle factors: Diet, alcohol use, and physical activity can influence breast cancer risk.

Pathophysiology:

Breast cancer arises when normal cells in the breast undergo mutations that lead to uncontrolled growth. This growth can spread (metastasize) to surrounding tissues or distant organs through the bloodstream or lymphatic system. The mutations are often related to the tumor suppressor genes like BRCA1/2, which control cell division and DNA repair.

Symptoms:

• Palpable mass: A lump or thickening in the breast.

• Change in breast shape or size: Asymmetry or distortion of the breast.

• Nipple discharge: Often bloody or clear.

• Pain or discomfort: Sometimes, though breast cancer can also be painless.

• Skin changes: Redness, dimpling, or skin puckering.

• Lymph node involvement: Swelling of the lymph nodes under the arm or near the collarbone.

Differential Diagnosis:

• Benign breast conditions: Fibrocystic changes, fibroadenomas, and cysts.

• Breast infections: Mastitis, abscesses, or breast inflammation.

• Trauma: Injury to the breast tissue causing a lump or bruising.

Investigations:

• Mammography: Recommended for routine screening, particularly for women over 50 or those at higher risk.

• Ultrasound: Often used to assess whether a lump is solid or cystic.

• Biopsy: Fine needle aspiration (FNA) or core needle biopsy to confirm malignancy.

• MRI: Used for high-risk patients or to further assess suspicious areas.

• Genetic testing: For patients with a family history of breast cancer, testing for BRCA mutations can be considered.

Management:

Surgical Treatment:

• Lumpectomy: Removal of the tumour with preservation of the breast.

• Mastectomy: Complete removal of the breast tissue.

• Sentinel lymph node biopsy: To check for spread to lymph nodes.

Adjuvant Therapy:

• Chemotherapy: To target and destroy cancer cells, often after surgery.

• Radiotherapy: Post-surgery to kill remaining cancer cells or reduce recurrence.

• Hormonal therapy: Tamoxifen or aromatase inhibitors for estrogen receptor-positive cancers.

• Targeted therapies: HER2 inhibitors (e.g., trastuzumab) for HER2-positive cancers.

Chemoprevention: For high-risk patients, medications like tamoxifen or raloxifene may be prescribed to reduce the risk of developing breast cancer.

Complications:

• Recurrence: Even after treatment, breast cancer can recur, often in the same breast or lymph nodes.

• Metastasis: Spread to distant organs, particularly the lungs, liver, bones, and brain.

• Lymphedema: Swelling of the arm or chest wall due to lymph node removal or damage.

• Psychological impact: Anxiety, depression, and body image issues can affect quality of life.

Prognosis:

• Early detection: Early-stage breast cancer has a high survival rate, with many patients living long, healthy lives post-treatment.

• Advanced-stage cancer: Poorer prognosis, with treatment focused on prolonging life and improving quality of life.

• Genetic factors: Patients with BRCA mutations may have a higher risk of recurrence or second cancers.

Risk of Genetic Predisposition:

• Jewish ancestry: Increased risk due to BRCA mutations.

• Family history:

  • Breast and ovarian cancer in the same person.

  • Breast cancer before 50 years old.

  • Bilateral breast cancer.

  • Male breast cancer.

• High-risk criteria:

  • 2 first-degree relatives with breast cancer (especially if <50 years).

  • Male breast cancer in the family.

  • BRCA1/2 mutations: Genetic testing should be considered for individuals with a strong family history of breast cancer or ovarian cancer.

Risk Categories for Screening:

Low Risk (1–1.5x):

• 1 first-degree relative >50 years

• 1 second-degree relative (any age)

• 2 second-degree relatives >50 years

• Mammogram every 2 years from 50–74 years

Moderate Risk (1.5–3x):

• 1 first-degree relative <50 years

• 2 first-degree relatives (any age)

• 2 second-degree relatives (1 <50 years)

• Consider referral to family cancer clinic

• Consider annual mammogram from 40 years if 1 first-degree relative <50 years

High Risk (3x and above):

• 2 first- or second-degree relatives PLUS one of the following:

  • Bilateral breast cancer

  • Breast and ovarian cancer in the same person

  • Male breast cancer

  • Jewish ancestry

  • Age <40 years

• Referral to family cancer clinic for genetic testing.

• Consider prophylactic mastectomy or salpingo-oophorectomy.

Red Flag System:

• Any of the following score 1:

  • 2 or more relatives with breast cancer.

  • 1st-degree relative with breast cancer.

  • Age <50 years at diagnosis.

• If 2 red flags: Moderate risk.

• If 1 red flag: Average risk.

• High risk: Obvious when multiple red flags are present.

• BRCA1/2 Mutations:

  • Women: Increased risk of breast and ovarian cancer.

  • Men: Increased risk of breast and prostate cancer