Release of immunosuppressive substances after gastric resection is more prolonged than after mastectomy in humans.

The effects of gastric and breast cancer surgery on the systemic immune response, and potential correlations with cytokines in peritoneal fluid (PF) and wound fluid (WF) after surgery were investigated in humans. Twenty patients with gastric cancer and 13 patients with breast cancer were studied. Blood natural killer (NK) cell activity and serum soluble interleukin-2 receptor (sIL-2R) were assayed, and prostaglandin E2 and transforming growth factor-beta1 were measured in PF and WF. A prolonged decrease in NK cell activity was observed after gastrectomy compared with mastectomy. Serum sIL-2R levels were increased after gastrectomy, whereas no difference was observed after mastectomy. Cytokine levels in PF persisted on day 1 through 5 after gastrectomy, whereas in WF they dropped sharply on postoperative day 3. The systemic immune response was decreased longer after gastrectomy than mastectomy, and this immune modulation may be partly attributable to the presence of cytokines in local exudates.