Epithelial ovarian cancer and borderline tumors during pregnancy: a report from the International Network on Cancer, Infertility, and Pregnancy.

Objective: To describe the oncological and obstetrical outcomes of women diagnosed with borderline ovarian tumors or epithelial ovarian cancer during pregnancy.

Methods: This is an international retrospective cohort study. Patients were eligible for inclusion if they were diagnosed with borderline tumor or invasive ovarian cancer during pregnancy, with histologic confirmation either before or after delivery, and were registered in the International Network on Cancer, Infertility and Pregnancy database between 1982 and 2019.

Results: A total of 129 patients were included, of whom 69 (53%) with borderline and 60 (47%) with invasive cancer. Diagnosis was established in the first, second, and third trimesters in 59 (46%), 48 (37%), and 22 (17%) patients, respectively. In total, 47 (36%) patients did not receive any treatment during pregnancy. The majority of patients (64%) underwent surgery with or without chemotherapy during pregnancy. Birthweight was significantly lower in women who received chemotherapy during pregnancy as compared to those who did not (median birthweight 2528 g vs 3031 g, p = .01) Among patients with borderline tumors, 20 (29%) experienced a relapse of whom 2 subsequently died from the disease. The 5-year survival probability was 98.5% (95% CI 95.6 to 100). Recurrence was associated with incomplete surgical staging (p = .02). Among patients with epithelial ovarian cancer, the relapse rate was 25% and the 5-year survival probability was 83.6% (95% CI 74.3 to 94.1). The oncological outcome was worse for patients with advanced-stage disease (p = .03). In addition, 66% of patients who relapsed after pregnancy did not undergo adequate surgical staging.

Conclusions: Treatment of patients with ovarian cancer during pregnancy can result in favorable oncological and obstetrical outcomes. Better oncological outcomes are achieved when treatment adheres to the standard of care in non-pregnant patients, as those who did not undergo surgical staging experienced a higher relapse rate.