First public and private ovarian cancer register in Chile: Potential effect of national formulary inclusion and COVID-19 pandemic on survival outcomes.

e17586 Background: Ovarian cancer (OC) is considered the most aggressive gynecologic cancer, with a 5-year survival rate of 50.9%. In Chile, OC is considered a public health priority and treatment has been covered in the national formulary since 2013. Nevertheless, there are no OC registers in Chile that report treatment patterns and survival outcomes considering inclusion in the national formulary and the potential impact of the COVID-19 pandemic. The aim of this study was to describe the treatment patterns and survival outcomes in patients with OC diagnosed between 2010–2024 in Chile. Methods: This is a retrospective, observational study conducted using medical chart data from the oncology unit of two centers in Santiago, Chile: Pontifical Catholic University Cancer Center (UC) and Sótero del Río Hospital (SRH). UC is attended by both public and private patients, whereas SRH is only attended by public patients. Patients aged ≥18 years with a confirmed OC diagnosis between 2010 and 2024 were included. Treatment (surgery, chemotherapy, maintenance therapy) and outcomes (objective response rate, platinum sensitivity), progression-free survival (PFS) and overall survival (OS) were collected and described using SPSS and R. Due to the inclusion of OC in the national formulary (2013) and the COVID-19 pandemic (2020), PFS and OS were analyzed in total and stratified considering three periods based on patients’ year of diagnosis: 2010–2013, 2014–2019, and 2020–2024. PFS and OS are reported as median and other categorical variables are reported as frequency and proportions. Results: In total, 288 patients were included in this study: 205 (71.2%) from UC and 83 (28.8%) from SRH. After diagnosis, 277 (96.2%) patients received chemotherapy, with 124 (44.8%) receiving adjuvant therapy, 63 (22.7%) neoadjuvant therapy, and 89 (32.1%) palliative therapy; one (0.4%) patient had no information registered. All individuals received platinum-based therapy. In total, 191 (66.3%) patients underwent surgery, with 162 (84.8%) achieving R0 cytoreduction. Complete response was observed in 137 (47.9%) patients. Of those receiving chemotherapy, 186 (67.1%) were platinum sensitive. Twelve patients (4.2%) received maintenance therapy with PARPis and/or bevacizumab. In the overall population, a median PFS of 11.9 months and median OS of 47.4 months were observed. The median PFS was slightly higher after inclusion of OC in the national formulary and during the COVID-19 pandemic (2010–2013: 10.1 months, 2014–2019: 12.3 months, 2020–2024: 13.5 months), as well as median OS (2010–2013: 40.1 months, 2014–2019: 49.8 months, 2020–2024: 48.4 months). Conclusions: Many platinum-sensitive patients were observed in Chile. PFS and OS improvements were observed after OC was included in the national formulary and were not impacted by the COVID-19 pandemic. Funding: GSK (219517).