The role of staging and adjuvant chemotherapy in stage I Malignant ovarian germ cell tumors (MOGTs): the MITO-9 study

abstract

Background: Surgery followed by platinum-based chemotherapy is the standard of care for MOGCTs, except for stage IA dysgerminoma and stage IA grade 1 immature teratoma where surveillance only is recommended. The role of adjuvant chemotherapy and surgical staging is debated.

Patients and Methods: Data from 144 patients with stage I MOGTs were collected among MITO centers (Multicenter Italian Trials in Ovarian Cancer) and analysed.

Results: 55(38.2%) patients were affected by dysgerminomas, 49(34%) by immature teratomas, 26(18.1%) by yolk sac tumors and 14(9.7%) by mixed tumors. 73(50.7%) patients receive surgery plus chemotherapy, while 71 (49.3%) patients underwent surgery alone. The latter group included 32 dysgerminomas (14 IA-13 Ix, 3 IB, 2 IC), 34 immature teratomas (20 1A-13 IA grade 1, 6 Ix, 1 IB, 7 IC), 4 mixed tumors and 1 yolk sac tumor. 44 patients did not received chemotherapy, even if it would have been indicated by recommended approach. 94(65.3%) patients received peritoneal surgical staging. 23(15.9%) developed a recurrence. Incomplete surgical staging was associated with recurrence (p<0.05; OR 2.37) at Cox regression analysis. 7 patients died. 4 patients were affected by yolk sac tumors, 2 by mixed tumors and 1 by immature teratoma. 5 patients died for disease, 1 for acute leukemia and 1 for suicide. Prognostic parameters analyses showed that yolk sac component is a predictor for survival (p<0.05) Five-years OS rates were 96.8% and 88.7% in surgically staged and incomplete staged group, while 93.8% and 94.1% in standard treatment and in the surveillance group, respectively.

Conclusion: This study shows that surveillance seems not to affect survival; chemotherapy should be reserved for relapse resulting in high cure rate. Incomplete peritoneal surgical staging is associated with recurrence. Yolk sac histology worsens the prognosis.