Benefit of lateral lymph node dissection for rectal cancer: long-term analysis of 944 cases undergoing surgery at a single center (1975-2004).

BACKGROUND: Pelvic sidewall dissection (PSD) has the potential to decrease local recurrence so that PSD may be an effective strategy for lower rectal cancer. Therefore, it is important to investigate the validity of PSD for its potential clinical use in lower rectal cancer therapy and prognosis.

PATIENTS AND METHODS: The present study included all 994 patients with rectal cancer who underwent curative surgery from January 1975 until December 2004 at the Kurume University Hospital in Fukuoka. The patients were analyzed to determine whether lateral lymph node (LLN) metastasis was correlated with clinicopathological factors, and in the overall study population, 5-year disease-free survival (DFS), and the 5-years overall survival (OS) were analyzed.

RESULTS: In patients with stage 3a cancer there was no significant difference in DFS between those with and without PSD. On the other hand, in patients with stage 3b DFS was significantly worse with PSD than without PSD. We analyzed the DFS and OS according to the number of lymph nodes with LLN-positive metastasis. Those with fewer than three positive lymph nodes had a significantly better DFS and OS compared to those with three or more. Moreover, those with only ore region of positive lymph node had a significantly better DFS and OS compared to those with two or more regions.

CONCLUSION: These results demonstrate that PSD was of benefit for prognosis for patients with fewer than three positive lymph nodes, those limited to within only one region and LLN metastasis only.