Introduction: Identification of patients with hereditary nonpolyposis colorectal cancer (HNPCC) can allow colorectal cancer (CRC) prevention through colonoscopy and polypectomies. The purpose of this study was to report the clinical characteristics of HNPCC families in our registry.
Patients and method: HNPCC was identified using the Amsterdam criteria. Familial clustering of CRC and extracolonic cancers were investigated in families. Individuals at risk were offered annual colonoscopy, starting from the age of 25 years.
Results: Twelve HNPCC families were identified. There were 46 cases of CRC in 38 patients. The mean age at diagnosis of CRC was 45.4 +/- 12.7 years (range 25-73 years). In patients with documented disease, right-sided tumors predominated. Eleven patients with extracolonic cancer were identified (six tumors located in the endometrium). Of 43 at-risk individuals, 29 accepted surveillance.
Conclusions: Our data confirm the importance of the family history in identifying HNPCC. This study confirms previously described characteristics in HNPCC, namely, early age at onset of CRC, right-sided predominance, multiple synchronous and metachronous neoplasms, and increased extracolonic cancers. This is the first study of clinical data in a Spanish HNPCC registry.