Fundamental of Breast Cancer

Breast cancer is the most common cancer in women worldwide. One in eight women will develop breast cancer in their lifetime. The median age of diagnosis is 63 years of age, the most common types being infiltrating ductal carcinoma (80%) and lobular carcinoma (15%–20%). Ductal carcinoma in situ lesions are important precursor lesions for infiltrating breast cancer, where surgical treatment, endocrine therapy and follow up is warranted. Three breast cancer subtypes have been identified based markers on the tumors done mostly via widely available immunohistochemistry (IHC) and in-situ hybridization. Tumors that express estrogen and/or progesterone receptors are known as hormone receptor positive and account for 70% of all breast cancer. Those overexpressing human epidermal growth factor receptor 2 (HER2) and account for 15%–20%. The reminding 15%–20% lack estrogen, progesterone and HER2 expression and are known as triple negative breast cancer. Breast cancer staging is based on lymph node positivity and presence or absence of distant metastasis. Breast cancer treatment is selected based on staging and subtype. The development and implementation of screening techniques and improvement in cancer treatments has improved significantly patient outcomes for patients with breast cancer. Breast reconstruction was performed after modified radical mastectomy