LYMPHOCYTE SUBPOPULATION AND NATURAL KILLER CELL CYTOTOXICITY AFTER LAPAROSCOPIC ASSISTED RESECTION OF RECTOSIGMOID CARCINOMA—A PROSPECTIVE RANDOMIZED TRIAL

Abstract

We compared the lymphocyte subpopullation and natural killer cell cytotoxicity in patients after laparoscopic assisted resection with those after open resection of rectosigmoid carcinoma.Background: Laparoscopic assisted resection of colorectal carcinoma is technically feasible and less traumatic, the postoperative immunosuppression thus may be reduced and potentially beneficial to tumour surgery.Methods: Forty patients with rectosigmoid carcinoma, without evidence of metastatic disease and suitable for laparoscopic assisted resection were randomized to receive either laparoscopic assisted (20 patients) or conventional open (20 patients) resection of the tumour. Clinical parameters were recorded. Blood were collected before operation, 24 hours, 72 hours and 8 days after operation for lymphocyte subsets and natural killer (NK) cell cytotoxicity studies. Data were analyzed by intention to treat.Results: The demographic data of the two groups were comparable. Clinically the laparoscopic group had significantly earlier return of bowel function, earlier mobilization and required less analgesia. The lymphocyte subpopulations and NK cell cytotoxicity of both groups showed a typical suppression after surgery. The suppression of T cell activation and NK‐like T cells was significantly less after laparoscopic assisted resection than in the open group, while the difference in other lymphocyte subpopulation and NK cell cytotoxicity were not significant.Conclusion: This study showed that some cellular components of immune system were less suppressed after laparoscopic assisted than conventional open resection of rectosigmoid carcinoma. This may have implication on the patient survival.