Cáncer colorrectal hereditario no poliposo: tratamiento quirúrgico y análisis de genealogías Hereditary nonpolyposis colorectal cancer: surgical treatment and pedigree analysis

ackground: Hereditary nonpolyposis colorectal cancer (HNPCC) accounts for 3 to 5% of all colorectal cancer (CC). It is an autosomal dominant syndrome with 80% of penetrance for this disease. Aim: To analyze the pedigree and surgical treatment of HNPCC. Patients and methods: We retrospectively analyzed our database of CC selecting patients with HNPCC according to clinical criteria (Amsterdam II). We characterized our patient's pedigrees with telephonic interviews. Results: From 1111 patients operated on with CC we identified 13 (1.17%) with HNPCC. The mean age at diagnosis was 41.6 years (range: 23-75). Sixty two percent presented in International Union Against Cancer (UICC) stages I or II and none in stage IV. Seventy one percent of tumors were proximal to splenic flexure. In 5 patients the diagnosis of HNPCC was made postoperatively, after diagnosis of CC in their relatives. In all but one of the 8 patients with preoperative diagnosis of HNPCC, we performed a total colectomy. From the remaining 6 patients with partial colectomy, 2 developed metachronic CC. Two patients died of cancer. From 101 persons in the 4 families, 25 have developed neoplasia: 18 CC, 3 endometrial cancer and 4 other tumors. Twenty eight relatives were eligible for colonoscopic screening, but only 21% of them have been screened appropriately. Conclusions: Preoperative diagnosis should change the surgical treatment of HNPCC, preventing metachronic disease. Primary colonoscopic screening allowed us to diagnose CC in early stages, nonetheless most of eligible relatives have not followed recommended frequency for colonoscopy (Rev Méd Chile 2004; 132: 539-47).