In this Letter, the y-axis label of Fig. 4d should read ‘Event-free survival (%)’ rather than ‘Overall survival (%)’, as correctly described in the figure legend, main text and Methods. In addition, in the ‘Clinical and treatment data’ section of the Methods, the fourth sentence should read: “Treatment data were curated for the patients receiving one or more lines of either PARP inhibitor or immune checkpoint blockade therapy via free-text search of medical and pharmacy records followed by expert review in a subset of cases, as follows.” instead of: “Treatment data were curated for the patients receiving one or more lines of either PARP inhibitor or immune checkpoint blockade therapy via free-text search and expert review of medical records.”. Neither of these changes affects the data, results or conclusions of the Letter, and the original Letter has been corrected online.