Objective: To assess the efficacy of a hereditary non-polyposis colon cancer (HNPCC) identification and surveillance policy.
Methods: Familial clustering of colorectal cancer (CRC) and extracolonic cancers (ECs) was investigated in 1520 consecutive CRC patients and relatives. HNPCC was identified by Amsterdam criteria, and individuals at risk were offered biennial colonoscopy and other examinations, starting from age 25 years.
Results: Twenty-two HNPCC families were identified. The CRC prevalence was 27.8% (121/435), decreasing from 59.4% in the first generation to 24.4% and 8% in the second and third generation, respectively. Twenty-nine patients had multiple CRC and 34 patients (in 12 families) had ECs.A total of 199/331 at-risk individuals accepted surveillance. The mean follow-up was 48+/-32 months. CRCs were detected at first surveillance in four out of 199 surveilled individuals (2%); in two surveilled individuals (1%), three CRCs developed during follow-up. The overall CRC incidence was 7/199 (3.5%) in surveilled individuals and 5/132 (3.7%) in unsurveilled individuals. CRCs were less advanced in surveilled than in unsurveilled patients. Eleven individuals had 22 adenomas (one with high-grade dysplasia). Three individuals had adenomas at first surveillance; two of them and eight more individuals during surveillance. Seven surveilled individuals and six unsurveilled individuals, all belonging to families with a history of EC, had EC during the study period. All patients with CRC detected by surveillance are alive. One of the unsurveilled patients who had CRC died 18 months after the diagnosis.
Conclusions: Data confirm the importance of the family history collected in each patient with CRC for identification of HNPCC and support the efficacy of repeated colonoscopies for early diagnosis and prevention of CRC in at-risk members. Reasons for surveillance failure could be an accelerated progression of small adenomas and a lesion missing at colonoscopy. Longer follow-up is required to assess the efficacy of surveillance for EC.