Re-induction chemotherapy regimens in patients with recurrent central nervous system mixed malignant germ cell tumors

Background: The lack of a standard treatment approach has contributed to poor outcomes of patients with recurrent central nervous system (CNS) mixed malignant germ cell tumors (MMGCT). There are no data in the literature supporting optimal re-induction chemotherapy regimens that should be used for patients with recurrent CNS MMGCT. Methods: We conducted a literature review to explore the response rate of patients with recurrent CNS MMGCT to different re-induction chemotherapy regimens by searching PubMed from 1985 through November 2017. Tumors were classified according to Japanese, European, and North American prognostic group classifications determined at initial presentation. Results: Forty-two responses to various re-induction chemotherapy regimens reported in 38 patients were included. Two patients were inevaluable and their responses to re-induction chemotherapy were excluded. Thirty-five responses to various re-induction chemotherapy regimens were evaluable in 33 patients following a first relapse. Six (17%) responses were reported as complete or continuous complete responses, seven (20%) partial responses, two (6%) were stable disease, two (6%) were mixed responses, and 18 (51%) were progressive disease. Five of ten patients treated without platinum-based chemotherapy experienced tumor progression. There was a trend towards a higher rate of tumor progression among histological poor prognostic group patients, and among patients relapsing within 24 months of initial diagnosis; however, it was not statistically significant. Conclusions: The histological prognostic group and time to relapse may affect the response to re-induction chemotherapy. However, further studies with larger sample size are needed to examine these associations and determine the optimal re-induction chemotherapy regimens for patients with recurrent MMGCT.