Purpose: The efficacy of radiation therapy (RT) combined with tamoxifen (TX) was tested in patients diagnosed with diffuse brainstem gliomas in a multicenter trial.
Patients and methods: TX was administered orally (maintenance dose: 200 mg/m(2) per day) along with conventional local RT and then continued for 52 additional weeks. Survival, tumoral radiologic response, and toxicity were evaluated. Compliance was assessed using pharmacokinetic measurements.
Results: Of 29 patients, 27 completed RT (median dose, 54 Gy). Of 22 assessable patients, 11 (50%) had an objective radiologic response. The mean TX steady-state serum level was 2.44 micromol/L +/- 1.02 micromol/L. Only three patients completed the entire course of treatment without tumoral progression or significant toxicity. Common side effects included nausea and vomiting. Hepatotoxicity (five patients), neurotoxicity (two patients), venous thrombosis (one patient), bilateral ovarian cysts (two patients), and transient neutropenia (one patient) were also observed. Median survival was 10.3 months. Only four patients remain alive without tumoral progression. The 1-year survival rate (mean +/- SD) was 37.0% +/- 9.5%.
Conclusion: This treatment combination produced no significant change in the overall poor prognosis of these patients. Most tumors responded initially to treatment but recurred as the study progressed. A minority of patients seemed to benefit from the extended use of TX. Generally, treatment was well tolerated, with good patient compliance, but we recommend continuous close monitoring for side effects. Based on our poor results, we recommend that alternative treatments be tested in patients with this type of tumor.