Evaluation of preoperative criteria used to predict lymph node metastasis in endometrial cancer

Objective. To evaluate whether we could accurately predict lymph node (LN) metastasis with preoperative tests in endometrial cancer. Design. Retrospective study. Setting. Seoul National University Hospital, South Korea. Population. Three hundred patients with endometrial cancer who underwent surgical staging including lymphadenectomy between January 1999 and July 2007. Methods. We reviewed the medical records of 300 patients with endometrial cancer. The preoperative factors used to predict LN metastasis were as follows: old age (>= 55 years), serum CA-125 level [level >= 20 U/mL (if age < 50 years), level >= 28 U/mL (if age >= 50 years)], non-endometrioid histologic type and Grade 3, metastatic LN assessed by pelvic MRI or CT, and deep myometrial invasion assessed by pelvic MRI only. Logistic regression analysis was used to determine the significant predictive factors. Main outcome measures. Sensitivity/specificity and false positive/negative rates. Results. Thirty patients had LN metastasis. Although LN evaluation by pelvic MRI or CT and high CA-125 level were the significant independent predictors for LN metastasis, the sensitivity/specificity and false positive/negative rates for LN metastasis by these two combined preoperative tests were 86.7%/71.4% and 68.7%/2.7%, respectively. However, the sensitivity/specificity and false positive/negative rates for LN metastasis by six combined preoperative tests were 100%/28.9% and 84.6%/0%, respectively. Conclusions. The six combined preoperative tests are useful in selecting patients without LN metastasis in endometrial cancer. Lymphadenectomy could be avoided in about 29% of patients with endometrial cancer who have no LN metastasis by using six combined preoperative tests.