BACKGROUND: TWO types of helper T cells (Th), which are categorized as Th1 and Th2 on the basis of cytokine production, have been reported, Th1 cells produce interleukin (IL)-2 and interferon (IFN)-gamma, while Th2 cells secrete IL-4, IL-6, and IL-10, We assessed the intracellular cytokine profiles of CD3/CD4 positive lymphocytes (CD4(+) T-cells) in peripheral blood in patients with digestive cancers. METHODS: Peripheral blood samples were collected from 50 patients with digestive cancers and 35 healthy volunteers. The proportions of CD4(+) T-cells producing intracellular cytokines were determined using flow cytometry, RESULTS: The percentages (mean +/- SD) of CD4(+) T-cells producing IL-4, IL-6, and IL-10 in the cancer group (73.9% +/- 13.0%, 73.0% +/- 16.6%, and 58.0% +/- 21.0%, respectively) were significantly higher than in the healthy group (37.4% +/- 12.4%, 37.8% +/- 13.5%, and 34.0% +/- 14.1%, respectively; P <0.01), Proportions of CD4(+) T-cells producing IL-4, IL-6, and IL-10 in 10 patients undergoing curative resection had decreased significantly 1 month after surgery (P <0.01), No significant difference was noted between groups in the percentages of CD4(+) T-cells producing IFN-gamma. CONCLUSIONS: Th2-dominant status develops in cancer patients. Such lymphocyte evaluations could find applications in diagnosis and therapeutic monitoring of cancer patients. (C) 1999 by Excerpta Medica, Inc.