Screening reduces colorectal cancer rate in families with hereditary nonpolyposis colorectal cancer.

Abstract

The inherited susceptibility to hereditary nonpolyposis colorectal cancer (HNPCC) provides an opportunity for secondary prevention of colorectal cancer (CRC) in family members who are at 50% lifetime risk. The aim of this study was to evaluate the effectiveness of long-term screening during a 10-year period. The CRC and death rates were compared between two groups of asymptomatic at-risk members of 22 families with HNPCC: 133 subjects screened at 3-year intervals by colonoscopy or barium enema and sigmoidoscopy and 118 control subjects without screening. The screening was complete in 118 subjects (89%), whereas 18 control subjects (15%) had screening examinations outside of the study. CRC occurred in 6 study subjects (4.5%) and in 14 controls (11.9%; P = 0.03), a difference of 7.4% in favor of the study group, which corresponds to a reduction by 62% that is presumably because of polypectomies. The tumor stage was more favorable in the screening group with no deaths caused by CRC compared with 5 of 14 cases in controls. Overall, there were 6 and 12 deaths within the 10-year period in the study and control groups, respectively (P = 0.08). The 3-year interval screening more than halves the CRC rate in at-risk members of families with HNPCC and seems to prevent CRC deaths.