ABSTRACT
Objective:To correlate neoadjuvant radiotherapy and chemotherapy efficacy with changes in peripheral blood T lymphocytes in patients with advanced mid-to-low rectal cancer.Methods:A total of 106 patients with rectal cancer who received treatment in Jinhua Municipal Central Hospital from January 2019 to December 2020 were included in this study. Fasting venous blood was taken before neoadjuvant radiotherapy and chemotherapy and 7 days before surgery to measure the numbers of CD3 +, CD4 +, CD8 +, CD45RA + and CD45RO + cells using flow cytometry. The optimal cut-off point was determined using the receiver operating curve. The influential factors of tumor regression grade were analyzed using logistic regression analysis. Results:After neoadjuvant radiotherapy and chemotherapy, the numbers of CD3 +, CD4 +, CD8 + cells were (401.86 ± 138.65), (225.83 ± 87.17), and (155.84 ± 71.19) respectively, which were significantly decreased compared with before neoadjuvant radiotherapy and chemotherapy [(477.33 ± 141.74), (647.38 ± 203.19), (348.22 ± 113.75), t = 10.78, 11.17, 9.49, all P < 0.05]. There were no significant differences in the percentages of CD3 +, CD4 +, CD8 +, CD45RA + and CD45RO + cells between before and after treatment (all P > 0.05). The percentage of CD45RO + cells was significantly increased after neoadjuvant radiotherapy and chemotherapy. A higher percentage of CD45RO + cells led to a lower tumor regression grade ( P < 0.05). The receiver operating characteristic curve showed that the optimal cut-off point of the percentage of CD45RO + cells was 1.08. The area under the receiver operating characteristic curve was 0.774 ( P = 0.029), with a sensitivity of 82.5% and specificity of 69.6%. The logistic regression analysis revealed that the percentage of CD45RO + cells was significantly correlated with tumor regression grade ( P < 0.05). Conclusion:The percentage of CD45RO + cells in T lymphocyte subsets before and after neoadjuvant radiotherapy and chemotherapy is closely related to tumor regression grade. It can be used as an indicator to predict the sensitivity of neoadjuvant radiotherapy and chemotherapy. This study is of great innovation and science and provides a new idea for clinical practice.