As with overall survival, multivariate regression analysis to adjust for prognostic factors (age, gender, tumour type, and baseline Hb level) did not alter the treatment effect estimates (adjusted HR from 0.78 (95% CI 0.62, 0.99) to 0.81 (95% CI 0.64, 1.03)). Here, GSTM1 is linked to neoplasm.