Changes in circulating immunosuppressive cytokine levels of cancer patients after high intensity focused ultrasound treatment

Immunosuppression in a patient with malignant tumor is a major obstacle in cancer treatment. In this study, we investigated changes in the circulating level of all measured immunosuppressive cytokines in patients with malignancy before and after high intensity focused ultrasound (HIFU) treatment. Fifteen patients with solid malignancy were enrolled in this study and an enzyme-linked immunoabsorbent assay (ELISA) method was used to measure serum level of vascular endothelial growth factor (VEGF), transforming growth factor-beta 1 (TGF-beta 1), transforming growth factor-beta 2 (TGF-beta 2), interleukin 6 (IL-6) and interleukin 10 (IL-10), respectively before and 1 wk after HIFU treatment. Among them, seven patients had distant metastasis and the remaining eight had no metastasis. All patients received one-session HIFU treatment for primary cancer, including complete ablation in eight patients without metastasis, and partial ablation in seven patients with metastases. The results showed that serum immunosuppressive cytokine levels decreased after HIFU treatment, and there were significant decreases of VEGF, TGF-beta 1, and TGF-beta 2 before and after HIFU treatment. Compared with the values in the metastatic patients, serum levels of immunosuppressive cytokines were significantly lower in the nonmetastatic patients after HIFU treatment. It is concluded that HIFU can decrease tumor-secreted immunosuppressive cytokine production in addition to its direct tumor destruction. This change may lessen tumor-induced immunosuppression and renew antitumor immunity after HIFU in cancer patients.