XRCC1 and mucositis: - Risk of mucositis was increased in patients with XRCC1-399Gln allele genotypes both in the chemoradiotherapy (p = 0.035, HR = 1.72, CI = 1.03–2.86) and radiotherapy alone (p = 0.049, HR = 2.50, CI = 0.97–6.47) groups.