GSTM1 and anemia: In the FCM preoperative cohort, there was an increase in patients with normal preoperative Hb, from 14.4 to 45.7%, before and after FCM, respectively, a decrease from 31.7 to 9.6% in moderate anaemia and no cases of severe anaemia after FCM administration, while 7.7% of patients were severely anaemic before FCM treatment.