Two Studies Find Routine Mammography Saves Lives

Byrne agreed that the statistics were impressive. Regular screening "decreases deaths by over 30 percent, [with] limited harm and reasonable costs. Additionally, cancers are detected at an earlier stage, which means not only decreased mortality but also morbidity; the patient may not have to have chemotherapy or a mastectomy," she noted.

In the second study, Dutch researchers found that even after accounting for improved treatments for breast cancer, mammography screening programs still saved a significant number of lives.

The researchers found that adjuvant therapy (treatment given in addition to primary therapy such as surgery) reduced breast cancer deaths by about 14 percent in 2008 compared to no treatment. However, they also found that breast cancer screening every two years reduced deaths by an additional 15.7 percent.

Using a computer modeling program, the researchers estimated that adjuvant treatment reduced breast cancer deaths from 67.4 to about 58 per 100,000 women years (cumulative years during which study participants were followed). The addition of screening for women ages 50-75 further reduced deaths to about 49 per 100,000 women years. This means that adjuvant therapy plus screening reduced deaths by a total of 27.4 percent.

If screening were extended to women ages 40-49, deaths would be reduced by a further 5.1 percent, according to Rianne de Gelder, a graduate student and researcher at the Erasmus University Medical Center.

"The effectiveness of breast cancer screening has been heavily debated in the last couple of years. One of the arguments that critics have is that, since breast cancer patients can be treated so effectively with adjuvant therapy, the relative effects of screening become smaller and smaller," de Gelder explained in a meeting news release.

However, "our study shows that, even in the presence of adjuvant therapy, mammography screening (between age 50 and 75) is highly effective in reducing breast cancer deaths and, in fact, is slightly more effective than adjuvant treatment," she said. For that reason, "screening women of these ages should definitely continue."

Byrne agreed, noting as well that the sometimes onerous side effects of chemotherapy treatment make catching tumors early via mammography even more crucial. Chemotherapy can "result in a significant decrease in quality of life," she said. "However, this study shows, even in the presence of adjuvant therapy, mammography screening reduces breast cancer deaths."

De Gelder and her colleagues said further investigation is still needed to determine "the ideal age for starting screening, taking into account not only the effects, but also the risks and costs of extending the lower age limits."