PD-1抑制剂靶向治疗联合mFOLFOX6化疗方案在局部进展期中低位直肠癌术前新辅助治疗中的临床研究OA

Objective To investigate the efficacy and safety of programmed death-1(PD-1)inhibitor targeted therapy combined with the oxaliplatin+5-fluorouracil+calcium leucovorin(mFOLFOX6)chemotherapy regimen in the preoperative neoadjuvant treatment of locally advanced middle-low rectal cancer.Methods Elderly patients with locally advanced middle-low rectal cancer were divided into control group and treatment group according to the treatment method.Patients in the control group received the conventional mFOLFOX6 chemotherapy regimen,with one cycle every 2 weeks for a total of 4 cycles.Patients in the treatment group received the conventional neoadjuvant chemotherapy with the mFOLFOX6 regimen combined with the PD-1 inhibitor camrelizumab injection(200 mg intravenously infused on day 1 of each cycle),with one cycle every 2 weeks for a total of 4 cycles.The surgical intervention was undertaken 4-6 weeks following completion of the chemotherapy regimen.The short-term efficacy evaluation of solid tumors,malignant tumor markers,anorectal dynamics and surgical efficiency were compared between the two groups and the safety was evaluction.Results A total of 97 patients were recruited,with 54 assigned to the control group and 43 in the treatment group.After treatment,the objective response rates(ORR)were 25.93％(14 cases/54 cases)in the control group and 48.84％(21 cases/43 cases)in the treatment group;the disease control rates(DCR)were 57.41％(31 cases/54 cases)in the control group and 76.74％(33 cases/43 cases)in the treatment group,with statistically significant differences(P＜0.05).After treatment,the carcinoembryonic antigen(CEA)levels in the control group and treatment group were(3.27±0.48)and(2.75±0.43)μg·L-1,respectively;the carbohydrate antigen 199(CA199)levels were(22.19±3.17)and(19.80±2.94)KU·L-1,respectively.The above indicators demonstrated statistically significant differences between the treatment and control groups(all P＜0.001).After treatment,the rectal resting pressure(RRP)levels in the control group and treatment group were(11.36±1.75)and(13.95±2.03)mmHg,respectively;the maximal tolerable rectalvolume(MTV)levels were(142.97±18.39)and(135.43±15.96)mL,respectively;the rectal compliance(RC)levels were(3.13±0.58)and(2.75±0.39)mL·mmHg-1,respectively.The above indicators demonstrated statistically significant differences between the treatment and control groups(all P＜0.05).The incidence of postoperative complications was 20.37％(11 cases/54 cases)in the control group and 18.60％(8 cases/43 cases)in the treatment group,with no statistically significant difference(P＞0.05).Conclusion Preoperative targeted therapy with a PD-1 inhibitor combined with the mFOLFOX6 chemotherapy regimen can significantly improve the short-term efficacy of solid tumors,reduce tumor marker levels,optimize anorectal dynamics and quality of life in patients with locally advanced middle-low rectal cancer,with mild immunosuppression and good safety.