Symptoms of Breast Cancer
Some patients with breast cancer do present with symptoms. They are diagnosed when either the patient or the healthcare provider notices a mass in the breast, a mass in the axilla (under arm), or changes to the breast skin or nipple. Some masses in the breast are detected by patient self-examination of the breast. Not all masses or lumps in the breast are due to breast cancer, however. Benign lesions, such as fibroadenomas or cysts, can also cause lumps in the breast tissue. A lump in the axilla may represent a primary breast cancer, a benign neoplasm, or a metastasis to a lymph node. The skin changes that might be seen in some cases of breast cancer include dimpling, redness, scaling and ulceration, which may look like a large sore. Nipple changes that might be seen include nipple scaling or new nipple inversion.
Other patients have no symptoms of breast cancer. These patients are diagnosed on screening imaging such as mammography, magnetic resonance imaging (MRI), or ultrasound.
Risk Factors for Breast Cancer
There are a variety of genetic and environmental factors that can increase a person's risk for breast cancer. These factors include older age, female gender, personal or family history of breast cancer, known genetic mutations, reproductive and hormonal factors, and other environmental factors such as exposure to radiation.
Hormonal factors play a large role in a patient's risk of developing breast cancer. Since most breast cancers are driven to proliferate from exposure to the hormone estrogen, and woman's history of "estrogen exposure" over her lifetime can influence her risk of breast cancer. A woman's body usually starts producing estrogens at the start of menstruation (menarche) until menopause, with breaks in estrogen production during pregnancy. This is why physicians will ask detailed history questions such as age of first menstruation (menarche), number of pregnancies, and age of menopause.
In addition to hormonal factors, family history and genetics an important factor in assessing the risk of developing of breast cancer. However, it's important to note that over 80% of patients who develop breast cancer do not actually have a first degree relative who had breast cancer. There are specific genetic mutations that can predispose individuals to developing breast cancer and other cancers, and mutations in these genes can account for approximately 5% of all breast cancers. These genes include BRCA1, BRCA2, p53 and PTEN. Genetic testing is available for patients and families who fit the criteria for possibly carrying a mutation in one of these genes.