While the nation’s major guideline-issuing organizations have slightly differing recommendations about when a woman should start having regular mammograms, each advises women to consult their healthcare providers when making personal decisions.
In June, the American College of Obstetricians and Gynecologists (ACOG) revised its guidelines for women at average risk for breast cancer, advising health providers to begin offering mammograms and discussing the pros and cons with women beginning at age 40. Prior to this revision, the recommendation was to begin mammography at age 40. ACOG recommends that women have an initial mammogram no later than age 50.
The U.S Preventive Services Task Force recommends starting regular mammograms at age 50, and the American Cancer Society at 45. Both acknowledge that some women may wish to start earlier in their 40s. Recommendations regarding frequency vary from annually to every other year, with mammography stopping at age 75 or when life expectancy is less than 10 years. There are different screening recommendations for women who are at very high risk, such as those with a BRCA-gene mutation.
The flexibility and variation among guidelines "recognizes that risk for breast cancer — as well as treatment for breast cancer — varies among individuals so that the same screening regimen may not be applicable to all people," says Maggie DiNome, MD, director of UCLA Breast Health and chief of the Division of Breast Surgery.
The guidelines reflect an effort to balance the benefits and harms of mammography for women in their 40s, who need to weigh the chance of finding cancer against the greater possibility of a result that leads to additional imaging, and perhaps biopsy, for an abnormality that does not pose harm.
On the other hand, "younger women have dense breast tissue, so the chance of a false negative" — a mammogram that looks normal even though breast cancer is present — "is much higher for this population," notes Merja Clegg, MD, a UCLA primary-care physician in Marina del Rey.
Breast cancer is the most commonly diagnosed cancer and the second leading cause of cancer deaths among American women. The ACOG revised mammography guidelines acknowledge that mammography starting at age 40 has been shown to reduce breast-cancer mortality.
When advising their patients about mammography, physicians look at the patient’s risk for breast cancer. Factors that influence risk include the patient’s age, family history of cancer, age when beginning menstruation, age at menopause and previous breast problems.
The new guidelines allow physicians to factor their patients’ feelings about risk versus benefit into the equation. Ultimately, the best decision results when patient and physician make a shared decision, says Giovinetza Hasbun, MD, a family-medicine physician in Santa Monica. "It’s all about education. Our job is to be educators and have open discussions with our patients to address their questions and concerns."
UCLA is participating in a University of California-wide study to refine mammography guidelines. The five-year Wisdom study compares the benefits of annual mammography versus a customized interval that is based on individual factors, including a woman’s personal and family health history and her genetic profile. “As we move into a world of precision medicine, where we’re able to collect more individualized information about patients, we’ll have a greater ability to fine tune recommendations,” says Arash Naeim, MD, PhD, chief medical officer for clinical research and UCLA’s lead investigator for the study.