Objective       To investigate the efficacy of high intensity focused ultrasound (HIFU) treatment for the subcutaneously transplanted tumor of colorectal cancer in mice and its following influence on the expression levels of indicative markers IL-6 and IL-10.       Methods       Sixty BALB/C mice undergoing subcutaneous injection of colorectal cancer cells were employed to serve as subcutaneous tumor mice model. The mice were randomly divided into 6 groups

control group

and groups in 1

3

5

7 and 14 d after treatment. The mice of the later 5 groups were treated by type JC-200 focused ultrasound tumor therapy system. the mice were sacrificed in the corresponding time points for their eyeballs

tumor tissues and blood samples. HE staining was used to observe the pathological changes of the tumor tissues. ELISA and RT-PCR were employed to detect the levels of IL-6 and IL-10 in the serum and tumor tissue respectively.       Results        HIFU not only effectively ablated the tumor issue

but also exerted its effect on target zone over time exhibiting various pathological changes such as edema

hemorrhage

inflammatory cell infiltration

necrosis

and fibrosis. After HIFU ablation treatment

the levels of IL-6 and IL-10 were elevated in the peripheral blood and tumor tissue in the early stage

while tended to decrease over time. The serum level of IL-6 was increased significantly in 1

3

5 and 7 d after the treatment when compared with that of control group (P0.05)

but that was reduced enormously in day 14 (P0.05). The serum level of IL-10 was obviously higher in the days 1 and 3 than the control (P0.05)

and reached its peak at day 1

but no significant difference was seen in the days 5

7 and 14 when compared with control group.       Conclusion       HIFU treatment has effective impact on tumor tissue through its focused ablation effect

and causes the early up-regulation of IL-6 and IL-10 in the residual tumor tissue and serum

but in later

the treatment leads the decrease  of the former

while has no effect on  the latter.