Breast cancer is a malignancy that is often strongly influenced by age, family history, genetic factors, hormonal exposure, and lifestyle factors.
On physical examination, the patient usually demonstrates a firm breast mass, which may be associated with axillary lymphadenopathy, skin changes, and nipple discharge.
Asymptomatic patients may be diagnosed with breast cancer after abnormal calcifications and/or architectural distortion are noted on a routine screening mammogram.
Treatment requires a multidisciplinary approach, involving breast surgeons, medical oncologists, 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 nausea) are essential.
Primary invasive breast cancer is a malignancy originating in the breast(s) and nodal basins. 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 (tumour, 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. Stage IIB can be considered early-stage breast cancer if the tumour is >20 mm but ≤50 mm and has spread to 1 to 3 axillary lymph nodes (i.e., T2 N1 M0), or locally advanced breast cancer if the tumour is >50 mm with no axillary lymph nodal involvement (i.e., T3 N0 M0).
History and exam
Key diagnostic factors
- presence of risk 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 oestrogen exposure
- exogenous oestrogen/progestin exposure
- alcohol consumption
- radiation exposure
- benign breast disease
- increased breast density
- mild, moderate, or marked background parenchymal enhancement (BPE) on breast MRI
- reduced physical activity
- poor diet
- high socioeconomic class
- 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)
Krystal Cascetta, MD
Division of Hematology and Medical Oncology
Icahn School of Medicine at Mount Sinai
KC declares that she has no competing interests.
Amy Tiersten, MD
Division of Hematology and Medical Oncology
Dubin Breast Center of the Tisch Cancer Institute
AT is on the advisory board for Immunomedics, AstraZeneca, Novartis, Eisai, and Healthline. She receives research funding from Pfizer, Novartis, Genentech, Lilly, and AstraZeneca and does expert testimony work.
Dr Krystal Cascetta and Professor Amy Tiersten would like to gratefully acknowledge Dr Hope S. Rugo, Dr Amal Melhem-Bertrandt, Dr Gabriel N. Hortobagyi, and Dr Phuong Khanh H. Morrow, the previous contributors to this topic.
AMB, GNH, and PKHM declare that they have no competing interests. HSR receives research funding through the University of California from Novartis, Pfizer, Genentech, Macrogenics, Plexxikon, Merck, Nektar, and GSK. She has been reimbursed for travel by Novartis, Genentech, and Nektar. She has received speaker honorarium from Genomic Health.
Anees Chagpar, MD
University of Louisville
AC declares that she has no competing interests.
Gurhan Celik, MD
General Surgery Department
Istanbul Training and Research Hospital
GC is an author of a number of references cited in this topic.
Edward R. Sauter, MD, PhD
Breast and Gynecologic Cancer Working Group
Division of Cancer Prevention
National Cancer Institute
ERS declares that he has no competing interests.
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