[Effect of surgical trauma on NK cell activity in esophageal carcinoma after transmediastinal dissection vs. transthoracic en bloc resection].

In order to assess the impact of surgical trauma involved in the therapy of esophageal carcinoma on the cellular immune system, a perspective study was performed involving perioperative hematological parameters. The activity of natural killer cells and the serum concentrations of interleukin-2, interleukin-6 and TNF-alpha were measured in 12 cases of transmediastinal dissection and 10 cases of transthoracic en bloc esophageal resection and compared to values of a control group of thoracic and abdominal surgical patients with non-malignant maladies. Natural killer cells assume a central role in the non-specific immunological response in tumor patients. Their main function is the destruction of tumor cells via cytotoxic activities amplified by the release of interleukin-2 and TNF-alpha. Natural killer cell activity was measured prior to surgery and on postoperative days 4 and 10 using a standardized europium chloride release assay, utilizing K562 target cells. Lymphokines interleukin-2, interleukin-6, and TNF-alpha were also measured on postoperative days 1 and 7 using standardized ELISA assays. The activity of natural killer cells in our patient group sank significantly (P < 0.05) on postoperative day 4 and likewise in the control group and both study groups, activity sank to the original values. In the control group, natural killer cell activity averaged 45% of preoperative values, in comparison with an average of 63% following transmediastinal esophageal carcinoma resection (one cavity procedure), and transthoracic en bloc resection (two cavity procedure). On postoperative day 10, all groups displayed a significant reacceleration of natural killer cell activity (P < 0.05). Whereas transthoracic en bloc resection patients only reached 61% of preoperative values, transmediastinal dissection patients assumed 75%, and 77% was achieved by control group members. Transthoracic en bloc resection of the esophagus led to a more extreme reduction in cytotoxic cellular activity owing to the greater surgical trauma. Suppression of the immunological tumor resistance, especially in the vulnerable perisurgical phase, can have an indirect negative effect on the manifestation risk of hematogenic metastases owing to intraoperative tumor cell dissemination resulting from tumor manipulation and may thus be prognostically relevant.