Evaluation of patterns of progression on poly (ADP-ribose) polymerase inhibitor (PARPi) maintenance in ovarian cancer: a cross-sectional study

Despite improvement in progression-free survival with poly (ADP-ribose) polymerase inhibitors (PARPi) as maintenance therapy for ovarian cancer, many patients will eventually progress on therapy. Oligoprogression is uniquely suited to considerations of local consolidation therapy in this setting, but not commonly used in ovarian cancer. In this study we evaluated the proportion of patients on PARPi maintenance who developed limited sites of disease, the location of progression, and their natural history.From January 2006 to December 2020, natural language processing software (DEEP6AI) was used to identify 58 patients with ovarian cancer treated with PARPi maintenance after complete or partial response after surgery and platinum-based chemotherapy at our institution. Patients were assessed for presence and location of recurrence based on radiologic findings.The median patient age was 65 (IQR 57-71) years. Patients had a median of two lines of chemotherapy prior to starting PARPi. With a median follow-up of 48 (range 12-149) months, 32 (55%) patients had a recurrence on maintenance olaparib and 11 (34%) patients developed oligoprogression (≤3 sites). For the 11 patients with oligoprogression, three patients developed recurrence in one site, five in two sites, and three in three sites. The sites of oligoprogression were pelvic/periaortic nodal (27%), peritoneal (27%), liver (27%), lung/mediastinal (14%), and brain (5%). The median progression-free survival for the entire cohort was 6.0 months (95% CI 4.2 to 7.8); median overall survival was not met. There were no significant differences in overall survival (p=0.81) or progression-free survival (p=0.95) between patients with and without oligoprogression.One-third of patients on PARPi maintenance experienced oligoprogression defined as limited to ≤3 sites. These patients may benefit from local consolidation therapy. A larger dataset is needed to validate these findings to assess if trials investigating local therapy for these patients is of value.