Survival impact of lymph node dissection in endometrial adenocarcinoma: a surveillance, epidemiology, and end results analysis.

The therapeutic benefit of lymph node dissection (LND) in women with endometrial cancer remains controversial. The purpose of this study is to analyze the impact of LND on survival. Data were obtained from the Surveillance, Epidemiology, and End Results program of the US National Cancer Institute for the years 1988-2003. Women with adenocarcinoma of the endometrium who underwent surgery as primary management of their disease were eligible. Multivariate analyses of pertinent variables were performed for the end points of overall survival and cause-specific survival. Women included in the analysis were 42,184. The average frequency of LND was 31%, 40%, 47%, and 53%, for the years 1988-1991, 1992-1995, 1996-1999, and 2000-2003, respectively (P < 0.0001). On multivariate analysis, presence of LND was associated with overall and uterine-specific survival benefits with hazard ratios (HR) of 0.81 (P < 0.0001) and 0.78 (P < 0.0001) and removal of greater than 11 lymph nodes (LN) associated with a HR of 0.74 (P < 0.0001) and 0.69 (P < 0.0001), respectively. Further multivariate analyses demonstrated greater than 11 LN to associate with all other cause-specific and cardiac-specific survival benefits, with HR of 0.77 (P < 0.0001) and 0.82 (P = 0.0062), respectively. We conclude that the presence of LND and increased number of nodes dissected predicted for improved overall and uterine-specific survival in women with adenocarcinoma of the endometrium. Improved cause-specific survival was most pronounced for greater than 11 nodes removed and stage II or higher disease. The improvement in noncancer-related mortality with LND predicted by this data suggests the presence of inherit biases, and the need for caution in analyzing retrospective data.