Q: I am 42 and have always been concerned about developing breast cancer as my mother did when she was 65. I asked my internist and gynecologist about scheduling a mammogram, and they each gave me different advice about its value. Could you resolve the conflict between the two?
A: About one in eight women in this country will develop breast cancer during her lifetime, and roughly one-third of those with breast cancer will die of the disease. In women 50 years of age or older, there is universal agreement about the value of mammograms, which can detect early breast cancers before they can be felt on examination. Available information suggests that regular mammograms reduce deaths from breast cancer in this age group by approximately one third.
There is considerable difference of opinion, however, about the value of mammography in women before the age of 50.
The American Cancer Society recommends an annual breast exam and a mammogram every year or two after the age of 40.
By contrast, the National Cancer Institute issued a statement in January expressing the opinion that mammograms should be deferred until age 50. Their statement was based on the findings of at least eight long-term studies that showed no increased survival from breast cancer in women who had mammograms between ages 40 and 50.
The study suggests mammography may be less useful in detecting breast cancer in younger women because the smaller amount of fat and larger amount of glandular tissue in their breasts, compared with older women, may decrease the likelihood of detection.
Also, because breast cancers progress more rapidly in younger women than in older ones, a cancer is more likely to advance significantly in the time between mammograms in younger women.
Should your fear of breast cancer make you decide to go ahead with a mammogram, don't panic if you are informed that an abnormality was detected. Despite the relative rarity of cancer at your age, some type of abnormality is found in 15 to 20 percent of mammograms. A mammographic finding leads to the recommendation for a breast biopsy in only about 3 percent of women. Should you decide not to have a mammogram, don't forget to do regular self-examinations and get an annual exam by your doctor.
Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine.