Objective: To study the influence of preoperative chemoradiotherapy, preoperative chemotherapy, and operation alone on the cellular immunity in patients with middle or lower rectal cancer.
Methods: Ninety middle or lower rectal cancer patients were non-randomly divided into 3 equal groups: preoperative radiotherapy group, receiving conventional radiotherapy with a total dose of 30 Gy in 10 fractions completed within 2 weeks; preoperative chemoradiotherapy group, receiving 2 cycles of single-oral drug regimen (capecitabine 1000 mg/m(2) for 2 weeks as a cycle with an interval of 1 week) and then, i.e., 2 days later, receiving conventional radiotherapy as prescribed for the patients in the preoperative radiotherapy group; and operation alone group. Operation was performed on the patients of the former 2 groups 3 weeks after the completion of the relevant treatment. Blood samples were collected on the admission day, 1 day before operation, and 7 day and 1 month after operation. Flow cytometry was used to detect the levels of CD(3)(+), CD(4)(+), CD(8)(+), CD(4)(+)/CD(8)(+), and NK cells.
Results: There were no significant differences in the levels of CD(3)(+), CD(4)(+), CD(8)(+), CD(4)(+)/CD(8)(+), and NK cells before and after radiotherapy between the preoperative chemoradiotherapy group and preoperative chemotherapy group (all P > 0.05). 7 days after operation, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), and NK cells were degraded and the CD(8)(+) level was increased significantly (all P < 0.05) in all 3 groups. One month after operation, the levels of CD(3)(+), CD(4)(+), CD(4)(+)/CD(8)(+), and NK cells were all significantly higher and the CD(8)(+) level was significantly lower than those before operation and 7 days after operation (all P < 0.05)in all 3 groups. There were no significant differences in the T cell number and the proportions of different categories of cells at different time points in these 3 group (all P < 0.05).
Conclusion: Preoperative chemoradiotherapy and preoperative chemotherapy have no significant impact on the cellular immune function in the patients with rectal cancer.