Galectin-1 is a poor prognostic factor in patients with glioblastoma multiforme after radiotherapy.

Galectin-1, a radioresistance marker, was found in our previous study to be a prognostic factor for cervical cancer. The aim of current study is to determine the prognostic significance of the galectin-1 expression level in patients with glioblastoma multiforme (GBM) undergoing adjuvant radiotherapy (RT). We included 45 patients with GBM who were treated with maximal safe surgical resection or biopsy alone followed by adjuvant RT of EQD2 (equivalent dose in 2-Gy fractions) > or = 60 Gy for homogeneous treatment. Paraffin-embedded tissues acquired from the Department of Pathology were analyzed using immunohistochemical staining for galectin-1 expression. The primary endpoint was overall survival (OS). Patients with weak expression had a better median survival (27.9 months) than did those with strong expression (10.7 months; p = 0.009). We compared characteristics between weak and strong galectin-1 expression, and only the expression level of galectin-3 showed a correlation. The group with weak galectin-1 expression displayed a 3-year OS of 27.3% and a 3-year cancer-specific survival (CSS) of 27.3%; these values were only 5.9% and 7.6%, respectively, in the group with strong galectin-1 expression (p = 0.009 and 0.020, respectively). Cox regression was used to confirm that the expression level of galectin-1 (weak vs. strong) is a significant factor of OS (p = 0.020) and CSS (p = 0.022). Other parameters, such as the expression level of galectin-3, Eastern Cooperative Oncology Group (ECOG) performance, gender, surgical method, age ≥ 50 years, tumor size, or radiation field were not significant factors. The expression level of galectin-1 affects survival in patients with GBM treated with adjuvant RT. Future studies are required to analyze the effect of other factors, such as O(6)-methylguanine-DNA methyltransferase (MGMT)-promoter methylation status, in patients with weak and strong galectin-1 expression.