Effect of Zinc Sulfate on Overall Survival and Progression-Free Survival in Patients with Glioblastoma Multiforme, a Phase II Study

Background: Glioblastoma is the most prevalent and aggressive adult glial tumor. Patients who receive standard treatment have a mean survival of 12-14 months. Zinc is a micronutrient that has shown to have anticancerous effects. In the in vitro studies zinc had antineoplastic effects on gliobalstoma cells. Method: This is a phase II randomized trial in which 60 patients in two groups were evaluated. The zinc group (29 patients) received zinc sulfate supplement 50 mg orally twice a day and the control group (31 patients) who were selected from historical case sreceived no supplements. Results: Mean overall survival in the case and control groups were 9.93 (+/- 3.29) and 9.0 (+/- 3.56) months. In the case and control groups, the mean disease-free survival were 9.62 (SD +/- 3.37) and 8.26 (SD +/- 3.47) months. These differences were not statistically significant. Although overall survival and recurrence-free survival in patients in the case group was higher than the control group, there was no statistically significant difference (P = 0.485). Conclusion: Zinc consumption was associated with better survival, but these differences were not statistically significant, necessitating further studies.