Breast Cancer Risk Factors

Early onset of menses and late menopause: Onset of the menstrual cycle prior to the age of 12 and menopause after 50 causes increased risk of developing breast cancer.

Diets high in saturated fat: The types of fat are important. Monounsaturated fats such as canola oil and olive oil do not appear to increase the risk of developing breast cancer like polyunsaturated fats; corn oil and meat.

Family history of breast cancer: Patients with a positive family history of breast cancer are at increased risk for developing the disease. However, 85% of women with breast cancer have a negative family history!

Family history only includes immediate relatives, mother, sisters and daughters. If a family member was post-menopausal (fifty or older) when she was diagnosed with breast cancer, the lifetime risk is only increased 5%. If the family member was premenopausal, the lifetime risk is 18.6%. If the family member was premenopausal and had bilateral breast cancer, the lifetime risk is 50%.

Genetic testing of the BRCA1 and BRCA2 genes is increasingly being integrated into clinical care for appropriately counseled adults who meet established criteria for this testing. The American Society of Clinical Oncologists (ASCO) and the National Comprehensive Cancer Network (NCCN) are among the professional healthcare organizations who have published criteria for genetic counseling/testing and cancer risk management. Increased and earlier surveillance, chemoprevention (tamoxifen, oral contraceptives) and surgical interventions (mastectomy, oophorectomy - removal of the ovaries and fallopian tubes) are among the current early detection and risk-reducing strategies discussed with women undergoing BRCA testing. In contrast to breast cancer, there is no reliable early detection for ovarian cancer, which is often fatal due to late stage at diagnosis. Therefore, oophorectomy is generally recommended between ages 35-40 or upon completion of childbearing for women at high risk for ovarian cancer. Despite initial concerns about insurance coverage discrimination, many insurers, including major indemnity plans (BC/BS, Aetna, Kaiser, etc.) recognize the healthcare benefits of this BRCA testing and cover test and genetic counsultation fees when demmed medically necessary. To date, more than 10,000 women and men have had BRCA testing. Similar to other medical tests, BRCA test results are often used to substantiate the need for the early detection and risk-reducing options available for individuals at high-risk for breast and ovarian cancers.

Late or no pregnancies: Pregnancies prior to the age of twenty-six are somewhat protective. Nuns have a higher incidence of breast cancer.

Moderate alcohol intake: Greater than two alcoholic beverages per day.

Estrogen replacement therapy: Most studies indicate that taking estrogen longer than ten years may lead to a slight increase in risk for developing breast cancer. However, these studies indicate that the positive benefits of taking estrogen as far as reducing the risk for osteoporosis, heart disease and now more recently Alzheimer's and colon cancer, far outweigh the slight increase in risk that may be associated with estrogen replacement therapy.

Caution should be exercised in those women with a significantly positive family history of breast cancer or atypical intraductal hyperplasia. Women with breast cancer are not currently give estrogen replacement. There are no scientific studies currently justifying this practice. However, until those studies are available, by convention, women are taken off estrogen.

History of prior breast cancer: Patients with a prior history of breast cancer are at increased risk for developing breast cancer in the other breast. This risk is 1% per year or a lifetime risk of 10%. The reason for close clinical follow-up after the diagnosis of breast cancer is not only to detect recurrence of the disease, but also to detect breast cancer in the opposite breast.

Female: The mere fact that being female increases the risk of developing breast cancer. However, for every 100 women with breast cancer, 1 male will develop the disease.

Therapeutic irradiation to chest wall i.e., for Hodgkins Disease (cancer of lymph nodes): Patients who have had therapeutic irradiation to the chest are at increased risk for developing breast cancer approximately 10 years later and consideration should be given to earlier screening in this population.

Moderate obesity: The relationship of breast cancer to obesity is more complex but associated with an increased risk.