Efficacy of Stump Irrigation in Removing Tumor Cells During Low Anterior Resection Using the Double Stapling Technique

BACKGROUND: In low rectal cancer, creating a permanent stoma can be avoided by applying a low anterior resection using the double stapling technique. However, the problem of local recurrence is still a major pattern of tumor recurrence in rectal cancer. We aimed to verify the clinicopathologic variables related to exfoliation of tumor cells and searched for an efficient method to remove the tumor cells from the rectal stump during a low anterior resection. METHODS: Forty-four patients who underwent a low anterior resection using the double stapling technique were enrolled prospectively. For patient, we irrigated each rectal stump twice with 500 cc of normal saline through the anus. Two specimens from each irrigation were obtained and examined for any malignant tumor cells. Cases in which no tumor cells were found from the two specimens were defined as Group I, cases in which tumor cells were found in only the first specimen were defined as Group II, and cases in which tumor cells were found in both the first and the second specimens were defined as Group III. Clinicopathologic variables were analyzed with regard to the presence of exfoliated tumor cells in irrigated saline. RESULTS: There were sixteen (36%), fourteen (32%), and fourteen cases (32%) in Groups I, II, and III, respectively, according to the examination results. Age classification (P=0.05) and metastatic lymph nodes (P=0.013) were associated with the presence of tumor cells in irrigated saline (I vs. II, II). CONCLUSIONS: Stump irrigation during a low anterior resection using the double stapling technique is recommended as an easy and simple method to remove exfoliated tumor cells from anastomosis sites, although further study is necessary to elucidate the association between exfoliated tumor cells and local recurrence.

Characteristic Clinical Behaviors of and Prognosis for Mucinous Adenocarcinomas in the Colon and Rectum

PURPOSE: The clinical significance of a mucinous-type colorectal adenocarcinoma is still controversial. Mucinous colorectal adenocarcinomas have been suggested to have distinct clinicopathologic features, i.e., early-onset, right-side dominancy, and poor prognosis. We aimed to verify the biological behaviors of and survivals for mucinous adenocarcinomas compared with non-mucinous adenocarcinomas. METHODS: Using a database of colorectal cancers at Asan Medical Center between 1989 and 2000, we enrolled 121 mucinous adenocarcinoma and 2,289 non-mucinous adenocarcinoma patients in this study. Clinical, pathological characteristics of and prognoses for mucinous adenocarcinomas were analyzed and compared with those for non-mucinous adenocarcinomas, retrospectively. The median follow-up period was 24 (0~113) months for mucinous adenocarcinomas and 32 (0~130) months for non-mucinous adenocarcinoma. RESULTS: Compared to non-mucinous adenocarcinomas, mucinous adenocarcinomas showed distinctive clinicopathologic features of early-onset (P<0.001), frequent family history (P<0.001), right-side dominancy (P=0.010), advanced stage at diagnosis (P<0.001), and common peritoneal seeding at diagnosis (P<0.001). The recurrence rate in the mucinous adenocarcinoma group was 45.2% during the follow-up period: 21.6% distant metastasis, 14.3% peritoneal dissemination, 5.7% local recurrence, and 3.6% simultaneous local recurrence and distant metastasis. The five-year survival rates in stages II and III were 70% and 48.7%, respectively, for mucinous adenocarcinomas and 92% and 50.2%, respectively, for non-mucinous adenocarcinomas. This difference was statistically significant. CONCLUSIONS: Mucinous adenocarcinomas seem to have distinct biologic behaviors with different clinicopathologic features and poor prognosis. A surgical approach with a follow-up schedule considering the characteristics of mucinous adenocarcinomas is needed.