Long term follow-up of a large series of stage-II/III atypical proliferative serous ovarian tumors

Background: The aim of this study was to assess prognostic factors and implications on further management in a large series of stage-II or III Atypical Proliferative Serous Tumors (APST) with a long-term follow-up. Patients and methods: Patients with APSTs and peritoneal implants treated in, or referred to, our institution were retrospectively reviewed. Prognostic factors on invasive recurrence, disease-free (DFS) and overall survival (OS) were analyzed. Results: Between 1971 and 2017, 212 patients were identified and followed (33 having invasive implants). After a median follow-up of 115 months, 70 recurrences were observed, 28 of them under the form of invasive disease. DFS at 5 years and 10 years was 73% and 62% respectively. The use of a conservative treatment (HR = 5.5[3.33–9.08], p <.0001), the presence of ≥3 peritoneal sites with implants (HR = 1.65[1.01–2.72], p =.045) were unfavorable prognostic factors for DFS. The presence of ≥3 peritoneal sites with implants (HR = 3.02[0.96–9.53], p =.049) and the presence of stromal microinvasion (HR = 3.19[1.12–9.1], p =.022) were unfavorable prognostic factors for OS. Non-conservative surgery (HR = 7[2.35–20.87], p =.0002), invasive implants (HR = 5.37[1.29–22.26], p =.013), and ≥ 3 peritoneal sites with implants (HR = 3.56 [1.11–11.39], p =.024) were identified as predictors of recurrence in the form of an invasive disease. Invasive implants were not associated with DFS (HR = 1.39[0.77–2.51], p =.27), nor OS (HR = 1.76[0.57–5.47], p =.32). Conclusion: After a long-term follow-up, type of peritoneal implants is no longer a prognostic factor for OS. Implants ≥3 peritoneal sites seem to impact significantly OS and then require a specific follow-up in this subgroup of patients.