Snapshot A 51-year-old woman presents to her primary care physician with a lump in her right breast. She says it has been there for around a year. Mammography shows a dominant mass with an irregular fibrotically stranded boundary, with some of the strands seeming to extend toward the nipple. A core biopsy was done and showed the following histology. Introduction Overview most common type of breast cancer infiltrating ductal carcinoma accounts for ~76% of breast cancer cases forms a solid tumor most common cancer diagnosis in women Epidemiology Demographics commonly women in mid-30s to late-50s Incidence 260,000 cases per year in U.S. 40,000 deaths per year Risk factors increasing age female sex breast cancer can occur in men < 3,000 cases per year in U.S. Caucasian race obesity in post-menopausal women hormone replacement therapy ETIOLOGY Genetics inheritance increased risk with BRCA1 and BRCA2 gene mutation mutations cancer cells can be estrogen (ER)-positive, progesterone (PR)-positive, or HER2/neu-positive guides targeted treatment Presentation Symptoms asymptomatic breast lump most often in upper/outer quadrant nipple discharge Physical exam firm immobile, painless lump +/- inverted nipple +/- skin changes redness ulcerations edema nodularity skin retraction indicates involvement of Cooper ligament axillary lymohadenopathy more advanced cases breast skin edema with dimpling ("peau d' orange") is a finding with a poor prognosis represents obstruction of the lymphatics cancer See Breast Cancer General Imaging Mammography indications regular screening mammography evaluation following detection of a breast lump findings mass with an irregular, fibrotically stranded border Core or excisional biopsy indications diagnosis findings gross pathology hard grey-white gritty mass invading surrounding tissue in an irregular stellate shape histology solid nest of neoplastic cells invading the surrounding structures more poorly differentiated = higher grade stains positive for E-cadherin Stage with TNM Staging System Studies Serum calcium level may be elevated Alkaline phosphatase elevation may indicate metastasis Hormone receptor tests ER PR Her2/neu Differential Invasive lobular carcinoma key distinguishing factors gross pathology often no mass lesion is evident histology individual invasive cells or cells in a single file negative E-cadherin staining Ductal carcinoma in situ (DCIS) key distinguishing factor no evidence of invasion on biopsy Treatment Medical chemotherapy indications tumors with high risk features locally advanced tumors neoadjuvant chemotherapy prior to lumpectomy modalities trastuzamab HER2/neu-positive tumors hormone therapy indications hormone receptor-positive tumors modalities tamoxifen or raloxifene ER-positive tumors reduces risk of metastasis radiation indications following breast lumpectomy Surgical modified radical mastectomy indications multicentric disease large tumor size in relation to breast presence of diffuse malignant-appearing calcifications on imaging prior chest radiation pregnancy positive margins after lumpectomy/re-excision lumpectomy indications smaller tumors relative to breast size patients who desire breast-conservinig therapy always followed by postoperative radiation therapy sentinel lymph node biopsy indications used for staging to detect spread of cancer must be performed prior to mastectomy if positive nodes detected and patient underwent lumpectomy, then sentinel lymph node biopsy may be performed again to search for additional nodes Complications Metastasis Recurrence majority of recurrences occur within first 5 years Death Prognosis Tumor size is most important prognostic factor Metastasis associated with poorer prognosis Second most common cause of cancer-related death in women