NATURAL-KILLER ACTIVITY AND SERUM IMMUNOSUPPRESSIVE ACIDIC PROTEIN-LEVELS IN ESOPHAGEAL AND GASTRIC CANCERS

The natural killer (NK) activity of peripheral blood mononuclear cells and serum immunosuppressive acidic protein (IAP) levels were examined in patients with esophageal or gastric cancer, before and after surge ry. Patients with stage IV esophageal or stage IV gastric cancer had s ignificantly lower NK activity (39.5 +/- 14.8% and 37 +/- 11.6%, respe ctively), and also higher serum IAP levels (778 +/- 264 mug/mL and 633 +/-156 mug/mL, respectively), than the corresponding control values ( 50 +/- 5.6% and 375 +/- 26 mug/mL, respectively). Patients with esopha geal or gastric cancer who underwent curative resection had high NK ac tivity (54.8 +/- 11.6% and 54.8 +/-8.0%, respectively), and low IAP le vels (471 +/- 116 mug/mL and 490 +/- 42 mug/mL, respectively), compare d with those who underwent non-curative resection. Patients who underw ent non-curative resection had lower NK activity and higher serum IAP levels than those who underwent curative resection, even 1 month after surgery. Mononuclear cells in the regional lymph nodes and tumor spec imens showed significantly lower NK activity than those in the periphe ral blood and spleen. Thus, NK activity and the IAP level reflected th e immunocompetence, clinical course, and surgical curability of those patients. NK cells appeared not to have any significant antitumor acti vity in the regional lymph nodes or in the tumor itself, although they were still active in the peripheral blood.