Objective: To study the effects of local hyperthermia on primary and metastatic focus.
Method: Animal tumor model was established in C57BL/6 mouse by injecting 5 x 10(5) Lewis lung carcinoma cells into the left foot pad. Ten days later, a tumor mass of 10 x 10 mm was seen, and local hyperthermia was performed at 37, 43, 45 and 47 degrees C for 30 minutes with water bath. 96 mice were randomly divided into four groups of 1, 2, 3, 4 weeks according to time of sacrifice. Every group had 6 mice.
Results: NK activity increased after 43-45 degrees C hyperthermia, and was higher than that of the control group (37 degrees C). The growth rate and lung metastasis decreased.
Conclusion: Host immunity is thought to be enhanced by local hyperthermia and plays an important role in eradicating primary tumor and controlling distant metastasis.