Primary site disease and recurrence location in ovarian cancer patients undergoing primary debulking surgery vs. interval debulking surgery

Introduction: The natural history and patterns of ovarian cancer (OC) relapse are still unclear. Recurrent disease can be peritoneal, parenchymal, or nodal. This study aims to analyze the location and pattern of OC recurrence according to the primary site of disease and to the type of surgical approach used. Material and methods: All OC patients underwent primary debulking surgery (PDS) or interval debulking surgery (IDS), with 2014 FIGO stage III-IV, and with platinum-sensitive recurrence were included in the study. Primary disease location and site of recurrences were divided into peritoneal, parenchymal, and nodal, according to the presence of peritoneal carcinomatosis, parenchymal metastasis, and nodal involvement, respectively. Results: A total of 355 patients were initially considered; of them, 295 met the inclusion criteria. Two hundred thirty-three patients obtained no macroscopic residual tumor at the end of primary surgical treatment. Primary parenchymal disease relapsed in 84.6% cases at a parenchymal site (p < 0.001), 97.2% of peritoneal diseases relapsed on the peritoneum (p < 0.001), and 100% of nodal diseases had a nodal recurrence (p < 0.001). Stratifying by the surgical approach all these correlations have been confirmed both in the PDS (p < 0.001) and IDS (p < 0.001) groups. Conclusion: Our study shows that the site of relapse in cases of platinum-sensitive OC recurrence is closely related to the primary location of the disease, regardless of the type of initial treatment. Therefore, more attention during followup should be paid to areas where the initial tumor was present.