Objectives To evaluate the survival impact of extensive lymphadenectomy as part of debulking surgery in stage IVB ovarian cancer with supradiaphragmatic lymph node metastasis.

Methods We retrospectively enrolled patients with stage IVB ovarian cancer who had 5 mm or larger lymph nodes in the supradiaphragmatic area including cardiophrenic, internal mammary and supraclavicular lymph nodes on computed tomography (CT) between January 2010 and January 2020, which were resectable evaluated by thoracic surgeon. Optimal debulking surgery (ODS) was defined as residual disease less than 5mm in both abdominal and thoracic cavities, and suboptimal debulking surgery (SDS) was defined as residual disease more than 5mm in abdominal or thoracic cavities.

Results A total of 121 patients underwent primary debulking surgery (PDS, n=68) and interval debulking surgery after neoadjuvant chemotherapy (IDS, n=53). Patients who underwent ODS showed better progression-free survival (PFS) than those who underwent SDS during PDS (median, 23.7 vs. 14.1 mons; p=0.035) despite no difference of PFS between ODS and SDS in those treated with IDS. Moreover, internal mammary or supraclavicular lymphadenectomy, bevacizumab administration and abdominal optimal cytoreduction were favorable factors for PFS in patients who underwent PDS (adjusted hazard ratios, 0.169, 0.185, 0.154; 95% confidence intervals, 0.059–0.484, 0.061–0.557, 0.043–0.550; p=0.001, 0.003, 0.004) despite no factors affecting PFS in those treated with IDS.

Conclusions Internal mammary or supraclavicular lymphadenectomy for ODS during PDS may have the potential to improve PFS in patients with stage IVB ovarian cancer with supradiaphragmatic lymph node metastasis.