Plasma levels of secretory IgA in patients with gastric cancer.

The levels of plasma secretory IgA were measured in patients with gastric cancer and found to be slightly higher (9.6 +/- 6.2 micrograms/ml) than those in healthy controls (7.0 +/- 2.6 micrograms/ml, 0.05 less than P less than 0.1). Secretory IgA levels in those with hepatic metastases (19.7 +/- 12.2 micrograms/ml) were significantly higher than those in patients without hepatic metastases (P less than 0.001). In the latter, there was no significant relationship between plasma secretory IgA levels and the deepest layer of cancerous invasion or lymph node metastases. The secretory IgA levels in cases of well differentiated tubular adenocarcinoma were significantly higher than those with poorly differentiated adenocarcinoma (P less than 0.05). Although there is small diagnostic value in the detection of gastric cancer by measuring the levels of secretory IgA, high levels of secretory IgA in gastric cancer patients may be indicative of the presence of hepatic metastases.