Significance of lymph node ratio on survival of women with borderline ovarian tumors

Purpose: To assess the qualitative and quantitative measures of the effect of pelvic lymph node involvement on survival of women with borderline ovarian tumors (BOTs). Methods: This is a retrospective study examining the Surveillance, Epidemiology, and End Results Program between 1988 and 2003. Women with stage T1-3 BOTs who had results of pelvic lymph node status at surgery were included. The effect of lymph node involvement on cause-specific survival (CSS) was evaluated using multivariable analysis with the following approaches: (1) any involvement, (2) involvement of multiple nodes (≥ 2 nodes), and (3) lymph node ratio (LNR), defined as the ratio of the number of tumor-containing lymph nodes to the total number of harvested lymph nodes. Results: A total of 1524 women were examined for analysis. Median count of sampled nodes was 8 (interquartile range 3–15), and there were 81 (5.3%, 95% confidence interval [CI] 4.2–6.4) women who had lymph node involvement. Median follow-up was 15.8 (interquartile range 13.8–18.9) years, and 83 (5.4%) women died of BOTs. After controlling for age, histology, stage, and tumor size, only LNR remained an independent prognostic factor for decreased CSS (adjusted hazard ratio [HR] per percentage unit 1.015, 95% CI 1.003–1.026, P = 0.014), whereas any involvement (adjusted HR 1.700, 95% CI 0.843–3.430, P = 0.138) and involvement of multiple nodes (adjusted HR 1.644, 95% CI 0.707–3.823, P = 0.249) did not. On cutoff analysis, LNR ≥ 13% had the largest magnitude of significance on multivariable analysis of CSS (adjusted HR 2.399, 95% CI 1.163–4.947, P = 0.018). Conclusion: Our study suggests that high pelvic LNR may be a prognostic factor associated with decreased CSS in women with BOTs.