Prognostic impact of lymphadenectomy in patients with advanced ovarian clear cell carcinoma: an ancillary analysis of the JGOG3017-A4 study.

BACKGROUND

Systematic pelvic and aortic lymphadenectomy in stage IIB-IVB patients with epithelial ovarian cancer, undergoing complete abdominal macroscopic resection with normal lymph nodes, was revealed to have no prognostic significance for survival in the LION trial. However, the proportion of patients with ovarian clear cell carcinoma (OCCC) in the LION trial was only 2.2%, so the significance of systematic retroperitoneal lymphadenectomy in patients with OCCC remains unclear.

METHODS

We conducted an ancillary analysis of 619 patients enrolled in a randomized phase III trial (JGOG 3017) in patients with OCCC. Of these, 89 were stage IIB to IVB, underwent a complete macroscopic resection, and had no grossly enlarged lymph nodes intraoperatively. Patients were divided into two groups: group A with lymphadenectomy and group B without lymphadenectomy. The Kaplan-Meier method was used to calculate progression-free survival (PFS) and overall survival (OS) and the log-rank test and Cox proportional hazard model were used to compare the two groups.

RESULTS

Among the 89 patients, 77 (86.5%) underwent a lymphadenectomy (group A), while 12 (13.5%) did not (group B). Three-year PFS were 62.3% in group A and 58.3% in group B (p = 0.7705). Three-year OS were 73.0% in group A and 65.6% in group B (p = 0.6346). No significant differences were observed between two groups.

CONCLUSION

This study did not demonstrate a definitive survival benefit from systematic lymphadenectomy in advanced OCCC patients with complete resection and clinically negative nodes. Given the small sample size, these results should be interpreted with caution and regarded as exploratory.