Age no bar to routine mammography

Evidence is accumulating that women in their 70s and beyond can benefit from regular mammograms. What does that mean for you?

Federal and other expert guidelines emphasize the importance of mammograms for detecting breast cancer early, when it's most treatable. Mammograms don't find every breast cancer, and they sometimes cause false alarms, but multiple trials have shown that routine screening can help save lives among women ages 50 to 69. What about older women, though? Should they keep getting regular mammograms? Until recently, there's been too little information to make a recommendation. Randomized trials of screening mammography generally exclude women ages 70 and over, and studies of cancer therapies rarely involve women over 65.

Instead of neglect, these decisions may reflect concern about the physical resilience of older women. Still, excluding them from studies is increasingly imprudent, given rising life expectancy and what we know about breast cancer incidence. Today, almost half of all women with breast cancer are 65 or over. The rate of new diagnoses is highest among women ages 75 to 79, and higher among women in their 80s, compared with those in their 50s. The ranks of older women are already growing, and the pace of growth will only increase as baby boomers age. Yet breast cancer–screening guidelines for such women remain sketchy.

Researchers concerned about the lack of information about mammography in older women have combed the medical literature and existing databases for answers. Their results suggest that age does not limit mammography's potential benefits — namely, earlier detection of breast cancer and reduced mortality.

The latest evidence

Using the National Cancer Institute's Surveillance, Epidemiology, and End Results, or SEER, program, researchers at M.D. Anderson Cancer Center in Houston looked at data from more than 12,000 women who were diagnosed with breast cancer in their 80s. They found that the women who had the most frequent mammograms (three or more in the five years before diagnosis) were diagnosed at an earlier stage and with fewer positive lymph nodes than the women who had fewer or no mammograms in the same period. These women were also more likely to be alive five years after the diagnosis (Journal of Clinical Oncology, May 20, 2008).

The Texas researchers cautioned against assuming a direct effect of screening on survival — women who choose to have regular mammograms tend to be healthier and have longer life expectancies anyway. But the finding is consistent with other studies. For example, at the European Breast Cancer Conference in April 2008, Dutch investigators presented data showing a steady decline in breast cancer deaths among women ages 75 to 79 who continued to have regular mammograms through age 75. And in the June 2007 issue of the journal Maturitas, researchers reviewing evidence on screening mammograms in women ages 75 and over reported that those who received annual mammograms during the two years preceding diagnosis — compared with those who had no mammograms — were more likely to be diagnosed at an earlier stage of breast cancer and were only half as likely to die of the disease.

Implications

Current mammography screening guidelines make no specific recommendations for women ages 70 and over, but the evidence suggests that many in this group would benefit from regular mammograms and should consider continuing to have them. There are also good public health reasons for such a step: the population is aging, and breast cancer risk increases with age. Moreover, mammography is generally more accurate in older women because their breast tissue is less dense. But there are potential downsides as well. False positives, which outnumber true positives, can lead to further uncomfortable tests, including biopsies that turn out to be negative. Also, breast cancer treatment can be harsh and adversely affect quality of life. Older women who already have serious illnesses or health risks may feel that undergoing mammography simply isn't worth the trouble.

So while it's good news that older women can potentially benefit from regular mammograms, the decision on continuing mammography remains an individual one, based not so much on age as on health status, personal preferences, and the possible benefits and risks of both screening and treatment. For help in making a decision, talk to a clinician familiar with your particular situation and personal risk profile.