Naoki Miyazaki

The impact of cytoreductive surgery on outcomes in high tumor burden ovarian cancer after induction of PARP inhibitors

In advanced ovarian cancer, achieving R0 resection is a critical strategy for improving prognosis. However, even with R0 resection, the prognosis of patients with a high tumor burden remains poor. This study aimed to assess whether the introduction of poly(ADP-ribose) polymerase inhibitors (PARPi) has enhanced outcomes in such cases. We retrospectively analyzed patients with International Federation of Gynecology and Obstetrics (FIGO) stage III-IV ovarian cancer treated between January 2015 and December 2021. Patients were classified into Group A (pre-PARPi introduction) and Group B (post-PARPi introduction). Complete macroscopic resection was defined as R0. Progression-free survival (PFS), stratified by the Aletti Surgical Complexity Score (Aletti_SCS), was the primary endpoint and was evaluated using Cox regression models. A total of 434 patients were included. In Group A, among those who achieved R0, the median PFS was 23.5 months for patients with high Aletti_SCS (95% confidence interval [CI]=14-30) and not reached for those with low Aletti_SCS (95% CI=30-not reached; adjusted hazard ratio [HR]=0.36, 95% CI=0.20-0.62). In Group B, the median PFS was not reached in both patients with high Aletti_SCS (95% CI=not reached-not reached) and low Aletti_SCS (95% CI=22-not reached; adjusted HR=4.98, 95% CI=1.14-21.78). Following the introduction of PARPi, there was a trend toward improved PFS in patients with a higher Aletti_SCS who underwent R0 resection. These findings suggest that R0 resection may improve prognosis even in cases with a high tumor burden in the PARPi era.