Is adjuvant chemotherapy indicated in ovarian immature teratomas? A combined data analysis from the Malignant Germ Cell Tumor International Collaborative.

BACKGROUND There is a debate regarding the management of ovarian immature teratomas (ITs). In adult women, postoperative chemotherapy is standard except for stage I, grade 1 disease, whereas surgery alone is standard in pediatric patients. To determine the role of chemotherapy, a pooled analysis of pediatric and adult clinical trials was conducted. METHODS Data from 7 pediatric trials and 2 adult trials were merged in the Malignant Germ Cell International Collaborative data set. Four trials included patients with newly diagnosed pure ovarian ITs and were selected (Pediatric Oncology Group/Children's Cancer Group Intergroup Study (INT 0106), Second UKCCSG Germ Cell Tumor Study (GC2), Gynecologic Oncology Group (GOG 0078 and GOG 0090). Adult and pediatric trials were analyzed separately. The primary outcome measures were event-free survival (EFS) and overall survival (OS). RESULTS One hundred seventy-nine patients were included (98 pediatric patients and 81 adult patients). Ninety pediatric patients were treated with surgery alone, whereas all adult patients received chemotherapy. The 5-year EFS and OS were 91% and 99%, respectively, for the pediatric cohort and 87% and 93%, respectively, for the adults. There were no relapses in grade 1 patients, regardless of the stage or age. Only 1 adult patient with a grade 2 IT relapsed. Among grade 3 patients, the 5-year EFS was 0.92 (0.72-0.98) for stage I/II and 0.52 (0.22-0.75) for stage III in the pediatric cohort (P = .005) and 0.91 (0.69-0.98) for stage I/II and 0.65 (0.39-0.83) for stage III/IV in the adult cohort (P = .01). Postoperative chemotherapy did not decrease relapses in the pediatric cohort. CONCLUSIONS The grade was the most important risk factor for relapse in ovarian ITs. Among grade 3 patients, the stage was significantly associated with relapse. Adjuvant chemotherapy did not decrease relapses in the pediatric cohort; its role in adults remains unresolved. Cancer 2016;122:230-237. © 2015 American Cancer Society.