Chemotherapy efficacy and prognosis of patients with mediastinal seminoma. Single institution experience.

Abstract

e16053 Background: Patients with mediastinal nonseminomatous germ cell tumors belong to poor prognostic group by IGCCCG. Mediastinal seminoma is very rare disease and data of the prognosis and chemotherapy efficacy are scarce. We retrospectively studied the outcome and prognostic factors of patients with mediastinal seminoma. Methods: We analyzed data of 39 (7.9%) patients with mediastinal seminoma from 493 patients with metastatic morphological verified pure seminoma and with normal AFP level and β-hCG < 500 mIU/ml, who were treated in our department during 1986-2014. Median age was 30 years (range: 15-64). All patients had good prognosis according IGCCCG. Medians β-hCG and LDH levels were 15 (range: 0.1-500) and 454 U/l (upper limit of normal is 450 U/l; range 120-2455), respectively. Metastasis were seen in 11/39 (28.2%) patients. Median follow-up time was 33.5 months (range 2-291). All patients were initially treated with chemotherapy; BEP/EP - 31/39 (79.5%), VAB6 or CP (cyclophosphamide/cisplatin) – 8/39 (20.5%) patients. Only 9/39 (23%) patients received < 4cycles of chemotherapy. Surgery resection of residual tumor was performed in 1/39 (2.6%) patient (histological report – necrosis). Statistical analyses was performed using Statistical Package for the Social Sciences Version 22.0 (SPSS Inc., Chicago, IL). Results: Marker negative objective response was revealed in 100% patients: complete response – in 9/39 (23%), partial response - 30/39 (77%) patients. A relapse (2.5%) occurred 12 years after the treatment. That patient was saved with salvage chemotherapy. One patient died from cardiac disease 9 years following chemotherapy. Three-year PFS and OS were 100%. Level of β-hCG (p = 0.4), LDH (p = 0.5), age (p = 0.9), number of cycles of chemotherapy (4 vs 2-3) (p = 0.6) did not alter the PFS. In addition, the scheme of regimen (EP vs BEP) did not influence on PFS – all cases are censured. Conclusions: Patients with mediastinal seminoma have an excellent prognosis in contrast to patients with mediastinal nonseminomatous germ cell tumors. Low number of relapses precluded analysis of prognostic factors.