Does local hyperthermia affect metastasis of a human prostate carcinoma grown in athymic nude mice?

Primary objective: This study investigated whether local hyperthermia increases metastasis of prostate carcinoma xenografts in athymic nude mice. Research design and methods: Human prostate carcinoma cells (1-LN-PC-3-1A) were injected into the animal's thigh. Mice were randomly divided into those treated with local hyperthermia (43degreesC for 45 min, tumour volume 100 or 200 mm(3)) and untreated controls, and sacrificed when the tumour volume reached 500 mm(3). Main outcomes and results: Histological evaluation (hematoxylin and eosin staining) of lymph nodes showed metastases in 20/21 hyperthermia-treated and 17/21 control mice. Lymph node involvement, tumour weight at sacrifice, and tumour growth rate were not significantly different between groups. Conclusion: Single local hyperthermia treatment had no effect on lymph node metastatic spread in this model.