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.