Cancer Screening Trials May Need All-Cause Mortality End Point LEBANON, N.H.--When it comes to interpreting randomized cancer-screening trials, the answers may depend on the perspective. A Dartmouth group that analyzed all 12 randomized cancer-screening studies for which both disease-specific mortality and all-cause mortality were available found that in five studies the results diverged significantly. The mortality rates went in different directions, suggesting opposite effects of screening, radiologist William C. Black of the Dartmouth-Hitchcock Medical Center here and colleagues reported in the Feb. 6 Journal of the National Cancer Institute. In four of the five trials, disease-specific mortality was lower in the screened group than in the control group, but all-cause mortality was the same or higher. In two of the other trials, the difference in all-cause mortality exceeded the disease-specific mortality in the control group. So disease-specific mortality, the investigators concluded, biases the trials toward the benefits of screening. And because all-cause mortality isn't affected by bias in classifying the cause of death, they suggested it should be factored with disease-specific mortality in interpreting the value of a cancer-screening test. The screening trials they analyzed included the seven of mammography that have been criticized heavily recently by Danish epidemiologists (who also looked at all-cause mortality), three of fecal occult blood detection, and two of chest x-ray screening for lung cancer. Defenders of the seven mammography-screening trials have criticized the Danish team for a reliance on all-cause mortality. "Disease-specific mortality may miss important harms (or benefits) of cancer screening because of misclassification in the cause of death," the Dartmouth team concluded. "Therefore, this end point should only be interpreted in conjunction with all-cause mortality. In particular, reduction in disease-specific mortality should not be cited as strong evidence of efficacy when the all-cause mortality is the same or higher in the screened group." In an accompanying editorial, Drs. Helen G. Juffs and Ian F. Tannock of Toronto's Princess Margaret Hospital noted that the investigators' suggestion to blend the two end points might reduce the size of the trials, lengthy follow-up, and great cost that would be needed for all-cause morality to show a benefit. But, they added, all-cause mortality may be the way to go. "We cannot justify implementation of screening programs that are costly to the individual and to the community if we are uncertain of their true benefit." CancerEducation.com NEWSLETTER For the week of Feb. 11, 2002 From Oncology Week in Review, Week of Feb. 11 Copyright ©2002 CancerEducation.com. All rights reserved JNCI, 2/02 Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.