Ask the Doctor: Heather Macdonald, M.D.

Q: How do I know if I’m at an increased risk for breast cancer?

A: Breast cancer is caused by the development of malignant cells in the breast. It can be invasive (invades the surrounding tissues) or noninvasive (does not invade the surrounding tissues). There are several factors that can determine if you are at an increased risk for breast cancer such as your family history and lifestyle.

As with many diseases, your risk of breast cancer increases as you get older. Approximately two out of three invasive breast cancers are found in women ages 55 and older. Women with close relatives who have been diagnosed with breast cancer also have a higher risk as approximately 10 percent of breast cancer cases are hereditary. If you have had a sister, mother or daughter who has been diagnosed with breast cancer, your risk is doubled. If you have a male relative with breast cancer or several relatives on the same side of the family with breast or ovarian cancer, you should ask your doctor to see a genetic counselor. Your family may be a candidate for genetic testing to clarify if there is an inherited gene for cancer running in the family.

Another factor is if you have had a breast biopsy that showed atypical hyperplasia, a precancerous condition that consists of an accumulation of abnormal cells in the breast. Atypical hyperplasia is not cancer but it can lead to you developing breast cancer, so your physician may recommend intensive breast cancer screenings and medications to reduce your risk.

Additionally, being overweight and not consuming a healthy diet increases your risks especially after menopause. Being overweight also increases your risk of breast cancer reoccurring if you have previously had the disease. To lower your risks, eat a healthy plant based diet, limit the amount of alcohol you consume to a maximum of four drinks per week, and do not smoke. Inactivity raises cancer risk regardless of body weight so make an effort to exercise regularly. A good benchmark is 75 minutes per week of strenuous exercise (think running or spinning) or 150 minutes per week of less strenuous exercise like brisk walking or yoga. You should also add weight bearing sessions every week to strengthen muscles and bones.

Long-term use of combination hormone replacement therapy (HRT) also places you are at higher risk for breast cancer. HRT was a popular treatment for postmenopausal treatment to ease menopausal symptoms, such as hot flashes, fatigue and bone loss; however, studies linked long-term multi-agent HRT use to small elevations in breast cancer risks in the early 2000s. Short-term use to ease the menopausal transition likely does not carry similar increases in breast cancer risk. If you take combination hormone replacement therapy for more than four years, ask your doctor if you are taking the type associated with breast cancer risk and consider alternatives.

If you have questions or concerns about your risk for breast cancer and what you can do to reduce it, please consult your physician.

Dr. Heather Macdonald is the medical director of the High Risk Program at Hoag Breast Center Irvine. As a board certified Obstetrician Gynecologist (OBGYN) and fellowship-trained breast surgeon, she focuses on breast disease diagnosis, surgical management of breast cancer, high risk patients and inherited breast cancer syndromes.