EP276/#774 Optimal cytoreduction and platinum-free interval affecting the duration of bevacizumab-based maintenance therapy and prognosis in the first platinum-sensitive recurrence of ovarian cancer

Objectives

Even though bevacizumab-based maintenance therapy (BMT) reportedly improved overall survival in the first platinum-sensitive recurrence of ovarian cancer, there was a lack of factors for predicting how long it will last. Thus, we investigated factors affecting the duration of BMT and their effect on the prognosis of the disease.

Methods

We included patients diagnosed with the first platinum-sensitive recurrence of ovarian cancer in two tertiary centers from January 2015 till August 2021. All patients received six cycles of paclitaxel-carboplatin-bevacizumab followed by BMT. We retrospectively collected data such as age, histologic type, status of BRCA mutation, platinum-free interval (PFI), extent of secondary cytoreduction, presence of extra-abdominal disease, number of recur lesions, duration of BMT, progression-free survival (PFS) and cancer-specific survival after the first recurrence (CSS).

Results

A total of 103 patients were included, and the median cycles of BMT was 13 (range, 1–108). Among them, 25 (24.3%) underwent optimal cytoreduction, whereas 4 (3.9%) and 74 (71.8%) received suboptimal cytoreduction or no surgery. PFI >12 months and optimal cytoreduction were factors for predicting 13 or more cycles of BMT (adjusted odds ratios, 3.334 and 4.675; 95% confidence intervals [CIs], 1.253–8.869 and 1.242–17.601), and improving CSS (adjusted hazard ratios [HRs], 0.064 and 0.121; 95% CIs, 0.011–0.355 and 0.181–0.837). Additionally, PFI >12 months was associated with better PFS (adjusted HR, 0.489; 95% CIs, 0.291–0.822).

Conclusions

PFI >12 months and optimal cytoreduction potentially predicted 13 or more cycles of BMT and were related to improved survival in the first platinum-sensitive recurrence of ovarian cancer.