1071 The pattern of radiological first platinum-sensitive relapse in ovarian cancer patients differs between different maintenance therapies: a retrospective analysis of a tertiary referral centre

Introduction/Background Despite optimal surgery and appropriate first-line chemotherapy, 70%–80% of patients with epithelial ovarian cancer will develop disease relapse. The aim of this study is to evaluate the radiological distribution of disease at the first recurrence in patients with advanced ovarian cancer treated with different maintenance therapies (PARP-inhibitors versus Bevacizumab). Methodology We retrospectively collected data on patients with recurrent advanced ovarian cancer from January 2017 to December 2022, who had III-IV FIGO stage at the diagnosis, a complete debulking (primary or interval surgery) followed by adjuvant chemotherapy and maintenance therapy. We included those with an available contrast-enhanced CT at the time of recurrence (clinical, serological or radiological). Recurrence was assessed at radiological imaging as: i) visible vs. non-visible solid tissue; ii) macronodular vs. micronodular pattern; iii) number of localisations (oligometastatic (Results We evaluated 80 patients; 40 had Bevacizumab and 40 had PARP-i. The incidence of recurrence without any clearly visible soft tissue was significantly higher during Bevacizumab (20% vs 10%; p=0.04). Micronodular diffuse relapse was more frequent in patients treated with Bevacizumab (58% vs 30%; p=0.03). Oligometastatic recurrence was more frequent in PARP-i (45% vs 24%; p=0.03). No difference was found in only nodal relapse between the two groups (18% vs 15%, p>0.05). Conclusion The recurrence pattern in ovarian cancer significantly differs based on the administered maintenance therapy at first line. This is a valuable information for clinicians to i) plan secondary cytoreduction; ii) avoid delayed diagnosis of recurrence in patients treated with Bevacizumab. Disclosures None.