Mammograms Up Odds of Saving Breast
When It's Cancer, Screened Women Have More Choices
Oct. 7, 2002 -- When the doctor says, "It's cancer," women who have regular mammograms are more likely to be offered breast-conserving surgery. The downside: they may also have more unnecessary surgeries.
The finding comes from a report at today's meeting of the American Society for Therapeutic Radiology and Oncology, ASTRO for short. Gary M. Freedman, MD, and colleagues at Philadelphia's Fox Chase Cancer center looked at nearly 1,600 women who found out they had breast cancer. All came to the Fox Chase "second opinion" clinic for evaluation of tumor size, tumor spread, and recommendations for treatment.
The women fell into three groups. The first group of 192 women had never had a mammogram before their tumor was found. A third of these women found out about their tumors when they finally got a mammogram. The second group of 695 women had previous mammograms but did not get them every year. The third group of 703 women had mammograms at least once a year.
The women who had the most frequent mammograms tended to have smaller tumors than women with less frequent mammograms. Taken together, the two groups of women who got mammograms had smaller tumors and less cancer spread to the lymph nodes than women who did not get mammograms.
Perhaps the most striking finding is that 61% of the women who got mammograms were offered breast-conserving surgery (lumpectomy) while only 29% needed full breast removal (mastectomy). In women with no mammograms, 41% were eligible for lumpectomy and another 41% needed mastectomy.
"I conclude there were benefits for screening mammography," Freedman tells WebMD. "Having yearly or more frequent screening had an edge in terms of having the lowest risk of an invasive tumor and in terms of small tumor size. We felt there was an edge to yearly screening. It was better than less frequent screening."
That's not the only possible interpretation of the data. Steven Goodman, MD, PhD, MHS, associate professor of biostatistics at Johns Hopkins Sidney Kimmel Cancer Center, points out that patients who had frequent mammography were much more likely to have a diagnosis of DCIS -- ductal carcinoma in situ. Not all DCIS will progress to invasive breast cancer within a woman's lifetime.
"This finding and claim is very problematic, because mammography is known to detect more DCIS which might not progress," Goodman tells WebMD. "Thus the mammography group includes women who might never have presented later [with breast cancer], and they are getting surgery they never would have gotten, breast-conserving or not. This study doesn't mean nothing, but it sheds little light on the mammography debate."
Freedman admits that the study is not a gold-standard clinical trial. But since experts are still debating the merits of mammography clinical trials, he says his study does indeed provide useful information.
Nearly all experts agree that women should begin having regular mammograms at age 50. Whether women age 40-49 benefit from such screening is a matter of heated debate. Freedman jumps into this debate with both feet.
"Even in the age 40-49 group, we saw significantly lower tumor stage and smaller tumor size in women who got mammograms," he says. "The recommendations for treatment did not reach statistical significance in this group. But if you look at the raw numbers there is a trend: breast-conserving surgery was recommended for 46% of the no-screening group, 53% in the partial screening group, and 58% in the frequent screening." -->