Surgery for colonic cancer in HNPCC: total vs segmental colectomy

Aim: The high reported risk of metachronous colon cancer (MCC) in hereditary nonpolyposis colorectal cancer (HNPCC) has led some authors to recommend total colectomy (TC) as the preferred operation for primary colon cancer, but this remains controversial. No previous study has compared survival after TC with segmental colectomy (SC) in HNPCC. The aim of this study was to determine the risk of developing MCC in patients with genetically proven HNPCC after SC or TC for cancer, and to compare their long-term survival.

Method: This is a prospective cohort study of all patients referred to our unit between 1995 and 2009 with a proven germline mismatch repair gene defect, who had undergone a resection for adenocarcinoma of the colon with curative intent. All patients were offered annual endoscopic surveillance.

Results: Of 60 patients in the study, 39 had TC as their initial surgery and 21 had SC. After 6 years follow up, MCC occurred in eight (21%) SC patients and in none of the TC patients (P = 0.048). The risk of developing MCC after SC was 20% at 5 years. Colorectal cancer-specific survival was better in TC patients (P = 0.048) but overall survival of the two groups was similar (P = 0.29).

Conclusion: Patients with HNPCC have a significant risk of MCC after SC. This is eliminated by performing TC as the primary operation for colonic cancer.