Breast cancer is a malignancy that is often strongly influenced by age, family history, genetic factors, hormonal exposure, and lifestyle factors.
The majority of patients are asymptomatic and present with abnormal calcifications and/or architectural distortion, or asymmetric density, on a routine screening mammogram.
Clinical breast exam may demonstrate a firm breast mass, which may be associated with axillary lymphadenopathy, skin changes, and nipple discharge.
Treatment requires a multidisciplinary approach, involving medical oncologists, breast surgeons, and radiation oncologists.
Complications of therapy are specific to each modality of treatment, and careful monitoring and preventive therapy for adverse events (e.g., antiemetic pre-medications in the prevention of chemotherapy-induced nausea) are essential.
Primary invasive breast cancer is a malignancy originating in the ducts or lobules. The term "invasive" indicates that the malignancy has penetrated past the basement membrane of the duct or lobule of the breast and has spread to the surrounding tissues, but has not spread to other organs.
The American Joint Committee on Cancer TNM (tumor, node, metastasis) staging system classifies invasive breast cancer into the following stages based on the extent of disease: IA, IB, IIA, IIB, IIIA, IIIB, and IIIC.
Stages IA, IB, and IIA are generally considered early-stage breast cancer. Stages IIIA, IIIB, and IIIC are generally considered locally advanced breast cancer.
Staging can also be defined by the pathologic node status (pN0 - pN3), which is dependent on the number of axillary nodes with metastases.
History and exam
Key diagnostic factors
- breast mass
- nipple discharge
- axillary lymphadenopathy
Other diagnostic factors
- skin thickening or discoloration
- retraction or scaling of the nipple
- increasing age
- female sex
- ethnic origin
- positive family history
- genetic mutations
- endogenous estrogen exposure
- exogenous estrogen/progestin exposure
- alcohol consumption
- radiation exposure
- atypical breast disease
- increased breast density
- mild, moderate, or marked background parenchymal enhancement (BPE) on breast MRI
- reduced physical activity
- poor diet
- high socioeconomic status
- high dibutyl-phthalate exposure
1st investigations to order
Investigations to consider
- breast ultrasound
- breast MRI
- hormone receptor testing
- HER2 testing
- gene expression assays
- computed tomography
- genetic testing
- alkaline phosphatase
early-stage breast cancer (stages I to IIB [T2 N1 M0])
locally advanced breast cancer (stages IIB [T3 N0 M0] to III)
- Fibrocystic changes
- Use of adjuvant bisphosphonates and other bone-modifying agents in breast cancer
- Exercise, diet, and weight management during cancer treatment
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