Pathology-oriented treatment strategy of malignant ovarian tumor in pregnant women: analysis of 41 cases in Japan.

Background: The aim of this study was to investigate the impact of the histological findings on the treatment of malignant ovarian tumors in pregnant women.
Methods: This is a retrospective study of 41 patients diagnosed and treated for ovarian malignancy during pregnancy between 1985 and 2010.
Results: The median age of the study group was 30 years old, ranging from 20 to 41. Thirty-eight (92 %) patients were diagnosed with stage I, and one (2 %) with each of stages II, III, and IV. Twenty-five (61 %) patients had borderline malignancy, 8 (20 %) were diagnosed with epithelial ovarian cancer, 7 (17 %) with germ cell tumor, and one with sex cord stromal tumor. All patients received primary surgery; 7 (17 %) patients had cystectomy, 32 (78 %) had unilateral salpingo-oophorectomy, and 3 (7 %) underwent hysterectomy with bilateral salpingo-oophorectomy. Thirty-one (76 %) patients delivered live newborns; 21 had borderline tumor (84 %), 2 had ovarian cancers (25 %), and 8 had non-epithelial tumor (100 %). Six cases were terminated in order to perform the standard treatment for ovarian malignancy and 2 cases aborted spontaneously.
Conclusion: In pregnant women, ovarian cancer is exceptionally less frequent compared with non-pregnant women, i.e. age-matched, statistically-corrected controls based on the Japanese annual report [8/33 (24 %) vs. control (60 %); ovarian cancer/(ovarian cancer + borderline tumor), P = 0.001]. The pregnant women with ovarian cancer chose to prioritize treatment of ovarian cancer at the sacrifice of their babies while those with borderline tumor or non-epithelial tumor were able to successfully deliver live newborns.