You may have heard this good news last week - that, in fact, a new study links the success of both mammography screenings and adjuvant therapies as contributors to the drop in cancer mortality during the previous three decades - even though the relative contributions of each has not been defined. The study was published in the Oct. 27 issue of The New England Journal of Medicine.
The findings are the result of the work of seven research groups that, though their approaches differed, each had the goal of determining the impact of screening mammography and adjuvant therapies related to the drop in breast cancer mortality in the U.S. from 1975 to 2000.
"The trials conducted to evaluate the effect of screening mammography on breast cancer mortality have been controversial. So the question was, do the findings from these studies translate into clinical practice," Donald A. Berry, MD, study lead author, M. D. Anderson Cancer Center in Houston, told Reuters.
Each research group found a survival benefit for both screening mammography and adjuvant therapies, and the benefits extend to tamoxifen and chemotherapy.
In the 25 years that were evaluated, breast cancer mortality dropped by as much as 21.3 percent, according to the report. Depending on the statistical model used, the mammography screenings accounted for 28 percent to 65 percent of the decrease. Thus, adjuvant therapies accounted for the rest.
"The results showed quantitative differences, but were qualitatively the same," said Berry, in comments regarding the study. He added, "It is certainly comforting for women to know that the benefits of adjuvant therapy from trials translate essentially unchanged into clinical practice. Although we are less certain about the impact of screening, the benefit is almost certainly there."