GSTM1 and mucositis: Compared to the subgroup with no treatment interruption, the subgroup with treatment interruption presented lower CRP levels but higher histidine concentrations before CCRT, experienced longer RT duration, developed more treatment-interval decreases in uric acid, Hb, albumin, ASM, and histidine, and had a higher proportion of patients with grade 3/4 mucositis toxicity.