The role of neoadjuvant chemotherapy in advanced-stage clear cell ovarian cancer: A GCIG multi-institutional...

To evaluate the impact of neoadjuvant chemotherapy (NACT) versus primary cytoreductive surgery (PCS) on surgical outcomes and survival in in patients with advanced clear cell ovarian cancer (OCCC).

We conducted a multi-institutional retrospective cohort study of 133 patients with FIGO stage IIIB-IVB OCCC treated between 2010 and 2024 at four tertiary cancer centers. Patients received either NACT followed by interval debulking surgery (n = 21) or PCS followed by adjuvant chemotherapy (n = 112). Statistical analyses included Wilcoxon rank-sum, Chi-square/Fisher's exact test, Kaplan-Meier estimates, and log-rank test.

Baseline characteristics were similar, although NACT patients had worse ECOG performance status (p = 0.019). Complete resection (RD0) was achieved in 48 % of NACT patients and 67 % of PCS patients (p = 0.21). Median PFS was 11.0 months with NACT and 12.4 months with PCS (p = 0.55); median OS was 23.0 and 27.4 months, respectively (p = 0.15). Cytoreduction to RD ≤10 mm was associated with improved OS compared with RD >10 mm (27.4 vs 10.0 months, p = 0.037), but not with improved PFS. Patients with RD0 had numerically longer OS and PFS compared to those with RD > 0, though not statistically significant.

In this multi-institutional cohort, advanced OCCC was associated with poor survival regardless of treatment approach. NACT did not significantly improve resectability or survival compared with PCS. However, maximal surgical effort and achieving RD ≤10 mm or RD0 were associated with better outcomes, underscoring the prognostic importance of cytoreduction and the urgent need for histology-specific trials.