Notably, in the case of tumor recurrences, the transfusion of blood components was independent from preoperative Hb values, and manifested an association solely with intraoperative blood loss (first recurrence: OR: 1.001 95% CI: 1.000-1.002; p = 0.001; second recurrence: OR: 1.003; 95% CI: 1.001–1.005; p = 0.002). This evidence concerns the gene GSTM1 and neoplasm.