A validation study of a scoring system to estimate the risk of lymph node metastasis for patients with endometrial carcinoma for tailoring the indication of lymphadenectomy

Abstract

5040 Background: The present standard treatment for cases with endometrial cancer is surgical staging including lymphadenectomy. Elimination of lymphadenectomy will not be approved of unless strict condition are met. Our aim is to verify whether a preoperative scoring system to estimate the risk of lymph node metastasis (LNM) in endometrial carcinoma is clinically useful for tailoring the indication of lymphadenectomy. Methods: This study was carried out on 211 patients with endometrial carcinoma for whom volume index, serum CA125 level, tumor grade/histology were preoperatively confirmed. LNM score was set up using these three risk factors as reported in our previous study (Am J Obstet Gynecol 2003). We analyzed whether these factors remain still valid in a different cohort of patients. Based on the LNM score before a validation study was started, the estimated rate of lymph node metastasis (para-aortic lymph node metastasis) in a low risk group was 3.4% (0.0%), an intermediate group 7.7% (5.8%), a high risk group 44.4% (30.6%) and an extremely high risk group 70.0% (50.0%). Results: Volume index, serum CA125 level, and tumor grade/histology, were found to be independent risk factors for LNM in the cohort of this validation study. The actual rate of lymph node metastasis (para-aortic lymph node metastasis) in a low risk group was 3.2% (1.0%), an intermediate group 15.3% (11.9%), a high risk group 30.2% (23.8%) and an extremely high risk group 78.6% (57.1%). Conclusions: LNM frequencies increased in proportion to the impact of the LNM score and the actual rate of lymph node metastasis for each score was quite consistent with the estimated rate of lymph node metastasis.Our LNM score for patients with endometrial carcinoma is useful. No significant financial relationships to disclose.