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

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 analyzed.

Results: Fifty-five (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. Seventy-three (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, and 2 IC), 34 immature teratomas (20 1A-13 IA grade 1, 6 Ix, 1 IB, and 7 IC), 4 mixed tumors and 1 yolk sac tumor. Forty-four patients did not received chemotherapy, even if it would have been indicated by recommended approach. 94 (65.3%) patients received peritoneal surgical staging. Twenty-three (15.9%) developed a recurrence. Incomplete surgical staging was associated with recurrence (P < 0.05; OR 2.37) at Cox regression analysis. Seven patients died. Four patients were affected by yolk sac tumors, two by mixed tumors and one by immature teratoma. Five patients died for disease, one for acute leukemia and one for suicide. Prognostic parameter 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 the surgically staged and the incomplete staged group, respectively, while 93.8% and 94.1% in the standard treatment and in the surveillance group, respectively.

Conclusions: 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.