HEREDITARY NONPOLYPOSIS COLORECTAL-CANCER - RESULTS OF LONG-TERM SURVEILLANCE IN 50 FAMILIES

A surveillance programme comprising either colonoscopy or sigmoidoscop y plus barium enema every 2-3 years was instituted in 50 hereditary no npolyposis colorectal cancer (HNPCC) families. The families included 2 38 patients with colorectal cancer (CRC) (mean age at diagnosis: 43.7 years; range: 16-86 years). These patients had 597 first-degree relati ves of whom 493 could be traced and 388 (79%) accepted the invitation for screening. The control group were relatives (index patients) with symptomatic CRC. The average follow-up duration was 5 years (1-20 year s). Screening led to the detection of adenomas in 33 patients and CRC in 11 patients. Pathological examination revealed 1 Dukes' A, 7 Dukes' B and 3 Dukes' C cancers. In contrast, among the control group 47% ha d advanced CRC (Dukes' C or distant metastases). The 5-year survival o f the screen-detected cases was 87% versus 63% in the control group. O f the 11 CRC cases in the screening group, 4 were detected within 1-4 years after a negative colonic examination. A large proportion of the polyps found in the screening and control groups showed a villous grow th pattern and/or a high degree of dysplasia. We conclude that periodi c examination of HNPCC families allows the detection of cancer at an e arlier stage than in patients not under surveillance. Because of the p ossibly more aggressive nature of polyps associated with HNPCC, we rec ommend a screening interval of 1-2 years.