Among hematological markers, anemia (Hb < 11.85 g/dL) and leukocytosis (WBC > 11.71 × 109/L) predicted shorter survival and remained independent predictors in the multivariable Cox model (HR 1.70, p < 0.001; HR 1.54, p = 0.004), along with T4 stage (HR 1.47, p = 0.015). Here, GSTM1 is linked to anemia (phenotype).