Breast Cancer General - Oncology - Medbullets Step 2/3

Snapshot
A 46-year-old woman presents to her primary care physician after discovering a lump in her left breast. She denies any breast pain or nipple discharge. Physical exam reveals a 2 cm firm, fixed mass in the left breast in the upper outer quadrant with no axillary lymphadenopathy.
Introduction
Overview second most common cancer (after lung cancer) most common cause of cancer-related death in adult women 12% lifetime risk Epidemiology incidence 260,000 cases per year most common in the elderly 50% of all breast cancer occurs in woman > 65 years of age 20% among women < 50 years of age 2% in women < 30 of age risk factors increasing age breast cancer in first-degree relatives or mother with breast cancer a low fiber, high fat diet obesity history of contralateral breast cancer a history of endometrial cancer which is also a estrogen induced cancer prior radiation increased number of menstrual cycles or exposure to estrogen nulliparity early menarche (< 11 years of age) late menopause (> 50 years of age) late first pregnancy (> 30 years of age) hormone replacement therapy physical/anatomic risk factors include (CHAFED LIPS) Cancer in breast Hyperplasia Atypical hyperplasia Female Elderly DCIS LCIS Inherited genes Papilloma Sclerosing adenitis prevention smoking cessation alcohol cessation exercise breastfeeding Genetics BRCA1 and BRCA2 mutations associated with multiple/early onset breast and ovarian cancer Prognosis dependent on stage and type triple negative (estrogen receptor (ER)/progesterone receptor (PR)-negative, HER2-neu-negative) has worse prognosis 40,000 deaths per year
Classification
Benign breast tumors intraductal papilloma bloody nipple discharge Carcinoma in situ LCIS not a premalignant lesion but considered a risk factor for breast cancer DCIS a premalignancy 50% develop into invasive ductal carcinoma Paget disease breast itching, crusting, and scaling > 80% associated with underlying breast cancer spreads lymphatically often transforms into invasive ductal carcinoma within 1 year Invasive carcinoma invasive lobular carcinoma invasive ductal carcinoma inflammatory carcinoma phylloides tumor 85-90% are benign may grow aggressively and recur locally
Presentation
History asymptomatic with recent screening mammography felt a breast lump Symptoms asymptomatic breast lump nipple discharge especially bloody, unilateral Physical exam firm immobile, painless lump most often in upper/outer quadrant skin changes (redness, ulcerations, edema, and nodularity) skin retraction indicates involvement of Cooper ligament axillary lymohadenopathy more advanced cases breast skin edema with dimpling (peau d'orange) represents obstruction of the lymphatics cancer poorer prognosis

Imaging

Mammography
- indications
  - screening
    - less effective in young women
      - dense breast tissue in young woman interferes with specificity and sensitivity
    - most effective in postmenopausal patients because of less glandular breast
    - all women aged 50-74 should have mammograms every 1-2 years
      - some recommend screening as early as age 40
      - if first-degree relative with cancer then begin screening ten years before family member developed cancer
    - screening for patients with breast implants is the same as general population
  - diagnosis
    - first step in work-up
      - patients > 30 years of age
      - bloody nipple discharge
      - recurrent cyst
      - 10-15% of palpable cancers are not detected on mammography
  - findings
    - mass
    - calcifications
      - present in 60% of cancers
    - follow up with core needle biopsy
Magnetic resonance imaging (MRI)
- indications
  - high risk women
    - prior radiation
    - BRCA gene mutation
- findings
  - breast mass
Ultrasound
- indications
  - patients < 30 years of age
  - cystic mass
    - follow up with fine needle aspiration

Tumor, Node, Metastasis (TNM) Staging

Staging is done with the TNM system and imaging (CT/bone scan)
Most important prognostic factor

TNM Staging
Nodes	None	Mobile Axiliary	Fixed Axiliary	Distant Mets
Size
> 5 cm	Stage IIB	Stage IIIA	Stage IIIA	Stage IV
2-5 cm	Stage IIA	Stage IIB	Stage IIIA	Stage IV
< 2 cm	Stage I	Stage IIA	Stage IIIA	Stage IV


Studies
Serum calcium level may be elevated Alkaline phosphatase elevation may indicate metastasis Hormone receptor tests estrogen progesterone Her-2/neu
Differential
Benign breast mass fibroadenoma most common mass especially common in younger women fat necrosis injury hardening of breast tisue secondary to injury to the breast intraductal papilloma bloody discharge Other cancer breast sarcoma lymphoma painless unilateral breast mass in an older woman
Treatment
Medical chemotherapy indications presence of metastases neoadjuvant chemotherapy prior to surgery target therapy for hormone receptor positive (ER and PR) and HER-2/neu oncogene trastuzamab adjuvant for HER-2/neu-positive cancer associated with reversible dilated cardiomyopathy endocrine therapy indications ER/PR receptor positive tumor radiation indications induction therapy to reduce initial tumor burden prior to surgery following lumpectomy to destroy any residual tumor cells Surgical lumpectomy indications smaller tumors patients with strong preference for breast conservation followed by radiation therapy mastectomy indications larger tumors prior history of chest radiation patients who desire mastectomy risk of nerve injury thoracodorsal nerve causes weak adduction and internal rotation long thoracic nerve causes winged scapula intercostobrachial nerve most common nerve injured causes reduced sensation to upper medial arm
Complications
Nerve damage during surgery Cancer recurrence Metastasis Death