CASE-CONTROL STUDY OF DIGITAL-RECTAL SCREENING IN RELATION TO MORTALITY FROM CANCER OF THE DISTAL RECTUM

The authors conducted a case-control study to examine the benefit of d igital-rectal examination in reducing mortality from distal rectal can cer. The Kaiser Permanente Medical Care Program provides prepaid medic al services to approximately 30 percent of the residents in its northe rn California service area, Members of the program aged 45 years and o ver who were diagnosed with fatal cancer of the distal rectum during t he period 1971-1986 and who died before 1988 as a result of their canc er (n = 172) and matched controls were selected for the study, Informa tion on digital-rectal examinations received in the absence of recorde d symptoms during the 10 years prior to the diagnosis date of the case was obtained from medical charts, Similar proportions of cases (20.9% ) and controls (23.3%) had been screened during the year before the di agnosis of the case (adjusted odds ratio = 0.96, 95% confidence interv al 0.56-1.7) and during longer intervals throughout the 10 years befor e the diagnosis date of the case, These results suggest no efficacy of digital-rectal examination for preventing mortality from rectal cance r, although a modest effect cannot be ruled out.