At univariate analysis, ECOG-PS (HR = 3.51; 95% CI, 1.86–6.63, p < 0.001), Hb levels (HR = 5.07; 95% CI, 2.18–11.76, p < 0.001), thrombocytosis (HR = 2.52; 95% CI, 1.05–6.01, p = 0.039) and hypercalcemia (11.08 vs. 4.37 months, HR = 3.24, 95% CI 0.31–8.03, p = 0.015) were significant predictors of OS, while at multivariate analysis, only ECOG-PS (HR = 2.33; 95% CI, 1.16–4.69, p = 0.018) and Hb levels (HR = 3.12; 95% CI, 1.18–8.26, p = 0.023) correlated with OS. Here, GSTM1 is linked to hypercalcemia disease.