April 22, 2008
Reuters Health

Mammography Benefits May Have No Age Limit

Women aged 80 and older who have regular mammograms significantly reduce their chances of being diagnosed with late-stage breast cancer, according to a new study. Yet only about 20 percent of women in this age group get mammograms regularly.

"This study suggests that mammography benefits may have no age limit and that women should consider being screened on a regular basis, even into their 80s and possibly 90s, depending on their current health status," study chief Dr. Brian D. Badgwell, MD, of the University of Texas M.D. Anderson Cancer Center said in a written statement.

"Mammography has been shown to be an excellent means of detecting breast cancer early, when it is most likely to be cured," he added. "We found that when breast cancer was diagnosed, it was more likely to be found at an early stage when a woman had at least three mammograms in the five-year period before diagnosis."

The American Cancer Society recommends annual mammograms beginning at age 40, with no upper age limit for women in good health. However, research has shown that women are less likely to get regular mammograms as they age.

Badgwell and colleagues examined mammography use in the five-year period before breast cancer was diagnosed in 12,358 women age 80 and older.

They found that only 22 percent of women were regular users of mammography, which they defined as having had three or more mammograms during the five-year study period. Twenty-nine percent were irregular users -- defined as having had one or two mammograms during the study -- and 49 percent of the women had no mammograms in the five years before their diagnosis.

Regular users were more likely to be diagnosed with early or "stage I" breast cancer, while stage II to IV breast cancers were more commonly found among the nonusers and irregular users.

Specifically, 68 percent of regular users were found to have stage I breast cancer, compared with 56 percent of irregular users and 33 percent of nonusers. On the other hand, only 32 percent of regular users had stage II-IV breast tumors, compared with 44 percent of irregular users and 67 percent of nonusers.

Ninety-four percent of women who got regular mammograms were alive at five years compared with 88 percent of irregular users and 82 percent of nonusers.

However, in their report in the Journal of Clinical Oncology, Badgwell and colleagues cautioned against linking mammography use to better survival, because survival from diseases other than breast cancer was also better among women who had regular mammography compared with irregular users and nonusers. This suggests, the researchers say, that women who got regular mammograms may be in a better state of health compared with women who don't get regular mammography.

It is estimated that about 17 percent of all breast cancer cases in the United States are found in women aged 80 and older. Badgwell and colleagues urge elderly women, particularly those in reasonably good health, and their health care providers to discuss the benefits of mammography.