Clinical Features and Survival Outcome of Patients with Malignant Transformation Arising in Mature Cystic Teratoma: A 20-Year Experience at Multicenter Institution and Literature Review on 342 Cases

Background: To analyze the clinicopathologic characteristics and prognosis in malignant transformation of mature cystic teratoma (MT-MCT). Methods: : We retrospectively reviewed 23 patients (cohort 3) diagnosed with MT-MCT from the medical center (Tongji Hospital and Hubei cancer hospital), between January 1990 to June 2020. Cohort 2 was obtained from the PubMed, CNKI, Web of Science, and MEDLINE database, between January 1990 to June 2020. Cohort 3 was based on the surveillance, epidemiology, and results registry (SEER) database, between January 1975 and December 2016. Results: : Among 3865 cases diagnosed with mature cystic teratoma, the incidence of MT-MCT is 23 (0.59%). The mean age of 23 patients was 50.6 years (median 49.0, range 24 to71 years). Patients mainly had abdominal pain (21.7%) or complained about an abdominal mass (30.4%). The mean tumor size was 11.6 cm (median 11.9, range 5.2 to 14.8 cm). According to the FIGO stage, eight patients were in stage I (34.8%), two cases were in stage II (8.6%), III (47.8%), and IV (8.7%), respectively. Most patients were diagnosed with squamous cell carcinoma (91.3%). Most patients received total hysterectomy, salpingo-oophorectomy, and omentectomy. Five patients (21.7%) received lymphadenectomy. Platinum-based chemotherapy and radiotherapy were selectively used for patients after surgical resection. The mean of disease-free survival was 27.3 months (median 22.0, range 3.0 to 67.0 months). According to the published data analysis of 342 cases, the 1-, 3-, and 5-year overall survival rates were 53.2%, 33.1%, and 23.2%, respectively. The young patients (＜55 years) showed better prognosis. Conclusion: MT-MCT has an aggressive clinical course, with poor long-term prognosis. The high incidence in postmenopausal women should not be ignored. The effectiveness of adjuvant chemotherapy or radiotherapy after surgery is needed to elucidate in the future.