Diagnosis

Breast cancer

Etiology

Cause [dku]

• 75% ductal carcinoma

• 15% lobular carcinoma

• 5% Medullary carcinoma

• 4% mucinous colloid carcinoma

• 1% tubular carcinoma

Pathophysiology [dku]

1. Sporadic (90%-95%) and genetic (5%-10%)

2. A series of DNA mutations at critical genes

3. Resulting in breast epithelial cells with immortal features and uncontrolled growth

Classification [dku]

• Estrogen receptor sensitivity

• Progesterone receptor sensitivity

• Human epidermal growth factor receptor 2 (HER2) sensitivity

• TNM:

  • T1: <2 cm. T1a: 0.1 to 0.5 cm. T1b: 0.5 to 1.0 cm. T1c: 1.0 to 2.0 cm

  • T2: 2 to 5 cm

  • T3: >5 cm

  • T4: T4a: Chest wall. T4b: Skin. T4c: Both 4a and 4b. T4d: Inflammatory ca

  • N1: Mobile ipsilateral axillary nodes

  • N2: Fixed/matted ipsilateral axillary nodes

  • N3: N3a: Ipsilateral infraclavicular nodes. N3b: Ipsilateral mammary nodes. N3c: Ipsilateral supraclavicular nodes

  • M1: Distant metastases

Risk Factors [dku]

• Increased exposure to estrogen

• Early menarche (< 12)

• Late menopause (> 55)

• Nulliparity or first pregnancy > 30 years

• White race

• Old age

• History of breast cancer in mother or sister

• Genetic predisposition (BRCA1 or BRCA2 positive, Li-Fraumeni syndrome)

• Postmenopausal estrogen replacement

• Radiation exposure

Epidemiology

Incidence per 100.000 [dku]

Approach

• Blood test [dku]

• Mammography

• Ultrasonography

• MRI

• PET

• FNA

• Biopsy

• BRCA

• Triple-negative: estrogen receptor, progesterone receptor, and HER2 receptor

Treatment

1. Early-stage breast cancer --> Surgery: Partial mastectomy or lumpectomy

2. Locally advanced breast cancer:

   • Preoperative (neoadjuvant) chemotherapy

   • Surgery (mastectomy) with axillary lymph node management

3. Adjuvant treatment to treat micrometastatic disease:

   • Radiation therapy

   • Chemotherapy

   • Hormone therapy: Anti-estrogen or aromatase inhibitor if hormone positive

   • Biologic agents

4. Metastatic breast cancer:

   • Hormone therapy

   • Chemotherapy

Differential diagnoses

Breast abscess, Cystosarcoma phyllodes, Fat necrosis, Fibroadenoma, Fibrocyst, Gynecomastia, Hidradenitis suppurativa, Intraductal papilloma, Mammary duct ectasia, Mastitis, Mondors disease, Paget's disease