Lateral lymph node dissection for lower rectal cancer.

BACKGROUND/AIMS: This study was conducted to evaluate the effects of lateral lymph node dissection (LLD) on overall survival, disease-free survival, and local recurrence for the patients with lower rectal cancer.

METHODOLOGY: From 1990 through 2000, 169 consecutive patients with T2 (TNM classification) or more advanced, extended lower rectal cancer (located below the peritoneal reflection) underwent curative resection at Kanagawa Cancer Center were reviewed. One hundred and forty-three patients who underwent LLD and the 26 patients who did not were entered in this study.

RESULTS: Cox's multivariate regression analysis showed T stage (TMN classification), N stage (TNM classification), and LLD were found to be significantly related to the rates of both cumulative survival and disease-free survival. That mean LLD was identified as a significant prognostic factor. But disease-free survival did not differ significantly between the patients who underwent LLD and those who did not undergo LLD in stage I, II, or III disease (p = 0.3681, p = 0.1815, and p = 0.0896, respectively). The local recurrence rate was similar in patients who received LLD (17.5 percent) and in those who did not receive LLD (23.1 percent; p = 0.498). But 7 patients with lateral lymph node metastasis (33.3 percent) remained disease free. And these patients had local lateral lymph node metastasis and benefited from LLD.

CONCLUSIONS: LLD can substantially improve outcomes in selected patients at high risk for lateral lymph node metastasis. A randomized controlled clinical study is necessary to clarify the role of LLD in the treatment of rectal cancer.