Resistance to platinum-containing chemotherapy in testicular germ cell tumors is associated with downregulation of the protein kinase SRPK1.

Male germ cell tumors (GCTs) are extremely sensitive to platinum-containing chemotherapy, with only 10% of patients showing therapy resistance. However, the biological basis of the high curability of disseminated GCTs by chemotherapy is still unknown. Recently, we demonstrated that the mammalian serine/arginine-rich protein-specific kinase 1 (SRPK1) is a cisplatin-sensitive gene, inactivation of which leads to cisplatin resistance. Because, in mammalians, the expression of SRPK1 is preferentially high in testicular tissues, cisplatin responsiveness of male GCTs might be associated with SRPK1 levels. In the present study, we monitored SRPK1 protein expression in a unique series of nonseminomatous GCTs by immunohistochemistry. Randomly selected GCTs (n = 70) and tumors from patients responding to standard chemotherapy (n = 20) generally showed strong SRPK1 staining. In contrast, expression in refractory GCTs (n = 20) as well as in GCTs from poor-prognosis patients responding to high-dose chemotherapy only (n = 11) was significantly lower (two-sided Wilcoxon rank sum test: P < .001). In conclusion, our data suggest that SRPK1 expression might be an important prognostic indicator for the chemoresponsiveness of nonseminomatous GCTs.

High-dose methotrexate, vincristine and cisplatin as salvage treatment for relapsed non-seminomatous germ-cell cancer.

Eight patients with non-seminomatous testicular cancer relapsing after primary chemotherapy were treated with salvage chemotherapy consisting of high-dose methotrexate (12 g/m2), vincristine (1.2 mg/m2) weekly for four weeks, followed after an interval of four weeks by 3 times 100 mg/m2 cisplatin (50 mg/m2 on day 1 and 2) every 10 days. This regimen resulted in 2 partial (PR) and 2 complete responses (CR). The two patients achieving CR remain disease-free for 43+ and 53+ months. Toxicity was mainly methotrexate-related and could be ameliorated to a large extent by leucovorin rescue. This small study shows that methotrexate, vincristine, followed by cisplatin is effective in the treatment of relapsed non-seminomatous testicular cancer at the cost of manageable toxicity.

Germ cell tumor in the hypothalamo-neurohypophysial region: clinical features and treatment.

Twenty-one patients with germ cell tumors (17 germinomas and 4 teratomas) involving the hypothalamic-neurohypophysial (HN) region were reviewed retrospectively. Eleven patients were males and 10 females, and their ages ranged from 7 to 45 years (average 18.5 years). Diabetes insipidus was the initial and the most prominent symptom in most germinomas; in teratomas the most prominent symptom was visual disturbance. Fifteen patients with germinomas were treated by radiotherapy, and 4 with teratomas were treated by surgical resection alone. Two recent germinoma patients with extensive CSF dissemination were treated with systemic chemotherapy consisting of anticancer platinum drugs and etoposide, which resulted in a complete disappearance of the tumors. Patients with germinoma treated after the introduction of CT scanning had a greatly improved mortality rate, and their actual survival rate was 87.5% over 10 years. On the basis of this review, the authors consider that diagnosis at an early stage of the disease and chemotherapy, which can be an effective therapeutic alternative to radiation therapy, may improve not only the mortality rate but also the quality of life of patients with HN germ cell tumors.