Therapy benefit seen besting mammogram

LITTLE ROCK — A new study in Norway suggests that increased awareness and improved treatments rather than mammograms are the main force in reducing the breast-cancer death rate.

Starting in their 40s or 50s, most women in the United States get a mammogram every year, as recommended by health officials. But the study suggests that the decision about whether to have the screening test may now be a close call.

The study, medical experts say, is the first to assess the benefit of mammography in the context of the modern era of breast-cancer treatment. It indicates that improved treatments with hormonal therapy and other targeted drugs mayhave, in a way, reduced most of mammography’s benefits by making it less important to find cancers when they are too small to feel.

Previous studies of mammograms, done decades ago, found they reduced the breast-cancer death rate by 15 percent to 25 percent, a meaningful amount. But that was when treatment was much less effective.

In the new study, mammograms, combined with modern treatment, reduced the death rate by 10 percent, but the study data indicated that the effect of mammograms alone could be as low as 2 percent or even zero. A 10 percent reduction would mean that if 1,000 50-year-old women were screened over a decade, 996 women rather than 995.6 would not die from the cancer - an effect so tiny it may have occurred by chance. The study, published Thursday in The New England Journal of Medicine, looked at what happened in Norway before and after 1996, when the country began rolling out mammograms for women ages 50 to 69 along with special breast-cancer teams to treat all women with breast cancer.

The study does have shortcomings. The ideal study would randomly assign women to have mammograms or not. But, cancer experts said, no one would do such a study today when mammograms are generally agreed to prevent breast-cancer deaths.

Nonetheless, the new study is “very credible,” said Dr. Barnett Kramer, associate director for disease prevention at theNational Institutes of Health.

In their study, the investigators analyzed data from all 40,075 Norwegian women who had received a diagnosis of breast cancer from 1986 to 2005, a time when treatment was changing markedly.

The investigators found that women 50 to 69 who had mammograms and were treated by the special teams had a 10 percent lower breast-cancer death rate than similar women who had had neither.

They also found, though, that the death rate fell by 8 percent in women over 70 who had the new treatment teams but had not been invited to have mammograms.