Risk factors for lymph node metastasis in ovarian cancer: Implications for systematic lymphadenectomy.

Background: The purpose of this study was to assess the risk factors associated with lymph node metastases and to evaluate the role of systematic lymphadenectomy in ovarian cancer.

Methods: We retrospectively reviewed patients diagnosed with ovarian cancer between December 2004 and March 2012. Demographics, pathologic findings, and correlations with lymph node metastases were assessed.

Results: A total of 256 patients were identified. The mean number of removed lymph nodes was 20.5 (range, 2-57), and 84 patients (32.8%) had nodal metastases. The mean number of positive lymph nodes was 3 (range, 1-40) in patients with lymph node metastases. Univariate analysis showed that serous histology, histological grade 2-3, and CA-125 level at diagnosis >740 U/mL were significant risk factors for lymph node metastases. Multivariate analysis showed that serous histology (odds ratio [OR], 2.728; 95% confidence interval [CI], 1.072-6.945; p = 0.035), histological grade 2-3 (OR 1.897; 95% CI, 1.209-2.977; p = 0.005), and CA-125 level at diagnosis >740 U/mL (OR, 3.858; 95% CI 2.143-6.947; p < 0.001) remain the most important risk factors for lymph node metastases. The nodal metastasis rates for 0 to 1 risk factors were significantly lower than those of 2-3 risk factors (3.7% vs. 40.6%; p < 0.001).

Conclusions: The current study suggests that the decision making of systematic lymphadenectomy in ovarian cancer patients should be referred to the histological type, grade, and CA-125 level at diagnosis.