To define the neoplastic risk in the remaining colon after proctectomy for rectal cancer in patients with hereditary nonpolyposis colorectal cancer (HNPCC).
The extent of surgery for rectal cancer in HNPCC is controversial. In determining which operation to perform, surgeons and patients must consider cancer risk in the remaining colon as well as functional consequences of removing the entire colorectum. The natural history of colon neoplasia in this situation is understudied and is not well-defined.
A single-institution hereditary colorectal cancer database was queried for patients meeting Amsterdam criteria and with rectal cancer. Patient demographics, surgical management, and follow-up were recorded.
Fifty HNPCC patients with a primary diagnosis of rectal cancer treated by proctectcomy were included. Detailed follow-up colonoscopy data were available for 33 patients. Forty-eight high-risk adenomas developed in 13 patients (39.4%). Five patients (15.2%) developed metachronous adenocarcinoma at a median of 6 years (range 3.5–16) after proctectomy, including 3 at advanced stage. One of these patients developed a high-risk adenoma before cancer. Mean interval between the last normal colonoscopy and cancer discovery was 42 months (range 23.8–62.1) with one developing within 2 years. Thus, 17 of 33 patients (51.5%) developed high-risk adenoma or cancer after proctectomy.
Surgeons and patients need to be aware of substantial risk for metachronous neoplasia after proctectomy. Selection of operation should be individualized, but total proctocolectomy and ileoanal pouch should be strongly considered. If patients undergo proctectomy alone, close surveillance is mandatory.
The risk of metachronous colonic neoplasia after proctectomy for rectal cancer in patients with hereditary nonpolyposis colorectal cancer (HNPCC) is understudied and remains incompletely defined. This study reports a 51.5% rate of high-risk adenoma or adenocarcinoma in the colon after proctectomy. Although surgical decisions need to be individualized, total proctocolectomy should be the preferred treatment for an index rectal cancer in a patient with HNPCC.
From the Department of Colorectal Surgery, and The Sanford R. Weiss, MD, Center for Hereditary Colorectal Neoplasia, Digestive Disease Institute, Cleveland Clinic, Cleveland, OH.
Reprints: Matthew F. Kalady, MD, Department of Colorectal Surgery, Digestive Disease Institute, Cleveland Clinic, 9500 Euclid Avenue, A30, Cleveland, OH 44195. E-mail: firstname.lastname@example.org.
Disclosure: The authors declare no conflicts of interest.
Presented at the Annual Meeting of the American College of Surgeons, October 5, 2010, Washington, DC.