With the exception of the WBC count, all blood and tumour markers (haemoglobin (Hb), β2‐microglobulin (β2 m) and LDH) were strongly associated with survival; each 10 unit (g/l) increase in Hb improving survival by 13% (HR = 0·87; 0·82–0·93) and each one unit (mg/l) increase in β2 m, decreasing survival by 14% (HR = 1·14; 1·07–1·21). This evidence concerns the gene GSTM1 and neoplasm.