GSTM1 and chronic kidney disease: Patient age, education, cancer stage, primary site of cancer, ECOG score, operating time, pre-operative WBC count, pre-operative Hb level, pre-operative RDW, pre-operative absolute lymphocyte count, pre-operative neutrophil proportion, pre-operative albumin level, pre-operative ALT level, comorbidity disease with chronic kidney disease, receiving adjuvant chemotherapy, receiving adjuvant radiotherapy, receiving nutritional supplement, and receiving albumin supplement all showed statistically significant differences between the low (≤45) and high PNI (>45) group.