Primary mediastinal seminoma.

Background: The objective of this study was to evaluate the long term treatment results of patients with primary mediastinal seminoma.

Methods: Sixteen patients aged 21-46 diagnosed with primary mediastinal seminoma between 1983 and 2014. Mean size of the tumor was 65 cm2 . In all patients gonadal involvement was excluded. In 6 patients, metastases to regional lymph nodes were found and none of them presented with distant metastases. HCG was elevated in 6 patients (38%). Eight patients underwent surgery as first-line of the treatment: 7 partial and 1 complete resection of the tumor. Chemotherapy (CTH) and radiotherapy (RTH) were methods of treatment in 14 cases. Tumor was irradiated to total dose of 36.0-50.4 (median 42.5) Gy. In statistical analysis overall survival (OS) was calculated using Kaplan-Meier method.

Results: During median time of 11 years of the follow-up, complete or partial regression (PR) of the tumor was seen in all patients after primary treatment. Recurrence of the tumor was seen in 3 patients. The 5-, 10- and 15-year local control rates were 75%. One was treated with CTH, other two with RTH. All of them responded with complete regression (CR) of the tumor. Three patients died during the follow-up. All others are alive without disease. The 5-, 10- and 15-year OS was 100%, 91% and 91% respectively.

Conclusions: Chemoradiotherapy of primary mediastinal seminoma gives satisfactory treatment results with good local control rate. The treatment outcome is comparable to primary testicular seminoma.