breast cancer

• Breast cancer


  A type of cancer that starts in the breast
• Breast cancer is the second leading cause of cancer death in women after lung cancer
• Breast cancer is an estrogen-dependent cancer
• Early detection of breast cancer

  • Patient awareness, regular physical examination, tumor markers, mammography (screening)

  
• Early detected breast cancer is usually curable, while metastatic breast cancer is usually incurable
• There is a strong relation between breast cancer and estrogen
• Breast cancer can occur in males but the incidence is very low (1:1000)
• Endocrine factors that increase risk of breast cancer

  • Early menarche (menstruation before or at 12 Y.O)
  • Late age at first baby (1st child at age of 30 or more)
  • Benign breast disease
  • Post menopausal estrogen replacement therapy
• Genetic factors that increase risk of breast cancer

  • Family history
  • Uterine and ovarian cancers
• Environmental and lifestyle factors that increase risk of breast cancer

  • Dietary fat
  • Alcohol consumption
  • Radiation exposure
• Tobacco and low concentration single hormone oral contraceptive use are not related to increased breast cancer risk
• The presence of more than one risk factor increases the risk of breast cancer
• Typical malignant breast mass

  • Unilateral
  • Solid or hard
  • Irregular
  • Non mobile

  
• Stabbing or aching pain is the first symptom in 10% of breast cancer cases
• Nipple discharge can be a symptom of breast cancer
• Symptoms of advanced breast cancer

  • Bone pain
  • Jaundice
  • Difficulty in breathing
  • Mental status changes
  • Abdominal enlargement
• Primary or curable breast cancer

  Localised breast lesion
• Micrometastasis


  Early deposits of tumor cells in axillary lymph nodes that cannot be easily detected
• Advanced or metastatic breast cancer

  Cancer cells detected in distant sites (lymph nodes, bone, liver, lung, brain, abdomen)
• The factors that determine metastasis are the size of the primary tumor and lymph node involvement
• Diagnostic tests for breast cancer

  • Careful history taking
  • Breast self-examination
  • Physical examination
  • Mammography
  • Ultrasound
  • Tumor marker (CEA)
  • Breast biopsy

  
• Staging of breast cancer

  Based on TNM system: Primary tumor size (T1,T2, T3, etc.), Lymph node involvement (N1-N2, N3, etc.), Presence or absence of metastasis (M0-M1)

  
• Stages of breast cancer

  • Stage 0 (in situ)
  • Stage I (localised)
  • Stage II (micrometastatic)
  • Stage III (locally advanced)
  • Stage IV (metastatic)
• 75% of breast cancer patients are diagnosed in stage I & II, 20% in stage III, and 5% in stage IV

  
• Prognostic factors for breast cancer

  • Primary tumor size
  • Presence and number of involved axillary lymph nodes
  • 5-year disease-free survival

  
• Hormonal receptors (HR)


  Cytoplasmic proteins that are clinically useful in breast cancer, the most important being estrogen receptor (ER)
• Interpretation of hormonal receptor levels

  • Less than 3 fentamoles/mg proteins (-ve)
  • From 3 to 10 fentamoles/mg proteins (intermediate)
  • Greater than 10 fentamoles/mg (+ve)
• Importance of hormonal receptor levels

  • Indicate dependence of cancerous cells on estrogen
  • Indicate need for hormonal therapy
  • Predict response and prognosis to hormonal therapy
• Hormonal receptor positivity is higher in post-menopausal women, making them more responsive to hormonal therapy
• Breast cancer is more aggressive in pre-menopausal women, who often have hormonal receptor negativity
• Desired outcomes of breast cancer treatment

  • Cure
  • Prevent recurrence or relapse
  • Improve symptoms and quality of life

  
• Treatment of early breast cancer

  Involves local-regional therapy (surgery and radiation) and systemic adjuvant therapy (chemotherapy for ER-negative, hormonal therapy for ER-positive)

  
• Surgical techniques for early breast cancer

  • Simple lumpectomy
  • Safety margin lumpectomy (partial mastectomy)
  • Complete mastectomy

  
• Surgery is often followed by radiation therapy to prevent recurrence
• Systemic adjuvant therapy


  Administration of systemic therapy after definitive local-regional therapy to prevent relapse and achieve cure
• Systemic adjuvant chemotherapy regimens

  • CMF (cyclophosphamide, methotrexate, 5-FU)
  • CAF (cyclophosphamide, doxorubicin, 5-FU)
  • AC (adriamycin, cyclophosphamide)
• Tamoxifen


  The current standard of care for systemic adjuvant hormonal therapy, acts by blocking estrogen receptors and reducing angiogenesis
• Tamoxifen therapy should be initiated shortly after surgery, except when combined with chemotherapy
• Tamoxifen is generally well-tolerated with less side effects than chemotherapy
• Oophorectomy (ovarian removal) is another anti-estrogenic therapy but less frequently used due to the availability of tamoxifen