In addition to having breast tissue and circulating estrogen, other risk factors have been identified that can increase breast cancer risk:
Although breast cancer has been known to develop in patients as early as their 20’s, most women develop breast cancer after the age of 50 with the median age of development in the US at age 62.
Although not pre-cancerous, certain conditions like atypical ductal hyperplasia (ADH) and lobular carcinoma in situ (LCIS) are considered high-risk lesions, and patients who are diagnosed with these conditions have an increased risk of developing a breast cancer in either breast during their lifetime.
A first-degree relative (mother, daughter, sister) with breast cancer, a male relative with breast cancer or multiple relatives on the same side with breast cancer increases a woman’s risk.
Because pregnancy naturally interrupts the fluctuating hormonal levels associated with menses, women who have never been pregnant are theoretically at higher risk for breast cancer development because they have had uninterrupted exposure of their breast cells to hormonal stimulation.
The reason behind this increased risk is not clear but it may be related to the amount of damage already incurred by the breast cells by the time of pregnancy, with advanced age having greater damage, which is then replicated in the cells as pregnancy drives cellular growth.
This increases the duration of exposure of breast cells to hormone stimulation.
Known mutations on genes that have been linked to increased breast cancer risk can be identified in patients with a simple blood test. Patients with known mutations in genes such as BRCA 1 or 2 are at increased risk for breast cancer development.