Mismatch repair protein expression and intratumoral budding in rectal cancer are associated with an increased pathological complete response to preoperative chemoradiotherapy: A case-control study

摘要

AIM To determine whether the association of rectal adenocarcinoma with a defective-mismatch repair system(dMMR) was associated with a pathological complete response(pCR) to preoperative chemoradiotherapy.METHODS A case-control study was designed with the aim of determining if patients with rectal adenocarcinoma with dM MR had an associated high pCR rate in response to neoadjuvant chemoradiotherapy(nCRT).RESULTS Seventy-two cases with pCR were compared against 144 controls without pCR. Across 216 cases, the mean age was 56.8 years, 140(64.8%) were men, and 63(29.2%) demonstrated the dMMR system. The pCR was associated with G1 tumors, dMMR, the absence of vascular invasion, and low tumor budding in the pretreatment biopsy. In a multivariant analysis, the factors associated with pCR were dMMR(OR: 2.61; 95%CI: 1.355-5.040, P = 0.004) and a low degree of tumor budding(OR: 2.52; 95%CI: 1.366-4.894, P = 0.025).CONCLUSION We found an independent association between dMMR and a low rate of tumor budding, with a higher rate of pCR, in the basal biopsies of patients with rectal carcinoma subjected to nCRT.