Effect of clinico-pathological features on prognosis in malignant ovarian germ cell tumors

Malignant over germ cell tumors (MOGCT) are responsible for 5% of all over cancers. The most important features of over germ cell tumors originating from primitive germ cells are their occurances in younger patients, malignancy of about 1/3 of them, low prevalence after third decade and more than half of the cases to be diagnosed at early stage. Objective: MOGCT should be investigated separately from other over tumors for its association to long-term survival, different pathways, and biological characteristics. In this study, we aimed to investigate the clinical and demographic characteristics of the patients who were followed up for MOGCT in the last 25 years in the University of Çukurova Medical Faculty, Department of Obstetrics and Gynecology and to research the prognostic parameters and the effect of findings on survival. Materials And Methods: Oncology files, clinical and pathological records of 115 MOGCT patients treated and followed-up between April 1992 and November 2017 were reviewed in our clinic. Clinical characteristics, operative information, frozen and pathologic findings, treatment and follow-up data of the patients were examined and the effect of these parameters on survival was investigated. Statistical analysis was performed using the Statistical Package for Social Sciences for Windows 20 (IBM SPSS Inc., Chicago, IL). Survival analyzes were performed using the Kaplan-Meier test. Total Survival (OS) and Disease-Free Survival (DFS) durations of grouped risk factors in malignant over germ cell tumors were noted both as mean and median, and statistical significance was assessed by using Log-Rank test. Independent factors predicting survival rate were studied using Cox regression analysis with backward selection method. Findings: The average age of the 115 patients included in the study was 27.5 +_ 14.3. The average follow-up period is 71.04 months. Among patients 40 (34.7%) had Dysgerminoma, 37 (32.1%) had Immature Teratom, 15 (13.04%) had Endodermal sinus tumor and 17 (14.8%) had Mixed Germ Cell Tumor histopathology. 69 of patients (60%) were diagnosed at the reproductive period and 70 (60.9%) were diagnosed as nulliparous at the time of diagnosis. The most common complaint was pain (47%) and abnormal uterine bleeding (27%). Fertility Protective Surgery (FPS) was performed in 55 patients (47.8%), complete staging surgery was performed in 38 patients (33%), and restaging surgery in 22 (19.8%) patients was performed in our clinic after operations were carried out in the external center. When we look at pregnancy rate in the postoperative period, although 79 patients wanted to stay fertile, only 55 underwent FPS, after which 19 (34.5%) of patients became pregnant and 15 of them had live births. The 5-year survival rate of the 115 patients studied is equal to 74%. Approximately 61 (53%) of the cases were Stage 1, 19 (16%) Stage 2, 28 (24.3%) Stage 3 and 6 (5.2%) Stage 4. Tumor localization was bilateral in 15 patients (13%). Histopathological differentiation of tumor tissue was good in 48 (41.7%) patients and poor in 28 (24.3%) patients. 71 (61.7%) patients underwent lymph node dissection. In 68 cases (60%), metastases were not detected at the time of diagnosis. Result: Of 1480 over-cancer cases in our clinic, 115 (7%) consist of MOGCT. During one-way analysis carried out within our study; tumor localization, non-performance of cytoreduction, advanced stage disease, poor differentiation, metastasis, mixed germ cell histological type, systemic disease of patients (diabetes, hypertension, asthma etc.) were determined as poor prognostic factors. Factors affecting disease-free survival in multivariate analyzes are advanced stage, tumor being mixed germ cell histology, and suboptimal cytoreduction. In our study, both disease-free and total survival period of mixed germ cell ovarian tumors were shown to be significantly lower than other histologic types. The high pregnancy rates after fertility surgery are hopeful for patients. Key Words: MOGCT, Overall Survival, Disease-Free Survival, Dysgerminoma, İmmature Teratom, Prognostic Factors