Q: There’s no history of breast cancer in my family. Now that I’m 40 years old, when should I have a mammogram?

A: Breast cancer accounts for 30 percent of all new cases of cancer diagnosed in women. In the United States, a woman’s lifetime risk of developing breast cancer is approximately 12 percent (1 in 8).

It is estimated that 252,710 new cases of breast cancer, resulting in 40,610 deaths, will be diagnosed in women in the U.S. in 2017.

The main risk factors for breast cancer are being female and advancing age. There are other factors that can increase your risk of breast cancer, such as greater body mass, higher alcohol consumption, never having been pregnant and going through menopause later in life.

Women with an average risk of breast cancer like yours should have a screening mammogram starting at age 40. You do not need to be screened any earlier. If you’ve never been screened, you should get a screening mammogram by age 50.

Mammograms help detect breast cancer early, when patients are healthy and have no symptoms. This can improve outcomes and survival rates and keep patients from needing more intensive treatments.

Beginning in your 40s, your risk of getting breast cancer and dying from it rises every year. But regular mammograms have been shown to improve your chances of surviving breast cancer, if you get it.

There are pros and cons to mammograms. The benefit is that they improve health outcomes. The downsides are the cost, anxiety over diagnosis, inconvenience, false-positive or false-negative results and possible over-diagnosis and over-treatment.

Women in their 40s should consider those cons carefully. The rate of breast cancer is much lower at this age, so mammograms may be less beneficial. Before you decide, weigh the potential benefit of reducing your chance of dying from breast cancer with the downsides listed above. For some, it will be worth the effort and cost.

You should talk to your ob-gyn about when to begin mammography screening. She can review your risk factors and explain the potential benefits and disadvantages of screening.

Joanne Price Williamson, M.D., FACOG, is an ob-gyn in practice at Provident OB/GYN Associates in Okatie.