Immune-related effects of local hyperthermia in patients with primary liver cancer.

BACKGROUND/AIMS To investigate immune-related effects of local hyperthermia (HT) with hepatocellular carcinoma (HCC). METHODOLOGY Immune status after 7 HT was studied in 11 patients (M/F - 9/2; 1st group). The effects were also evaluated during one HT session in 4 of those pts (M/F - 4/0; 2nd group). The HT treatment was performed by means of an 8-MHz capacitive heating device, Thermotron RF8 (Japan). The mean time of one HT session was 60 min, HT was performed 1-2 times a week. In both groups the percentage of T and B cells, CD4+, CD8+ subsets of T cells, the CD4/CD8 ratio and activation of NK cells were evaluated. RESULTS In the 1st group, CD4/CD8 ratio was decreased significantly (p < 0.05), whereas the relative amount of CD4+ T cells showed a tendency to decrease (p=0.063), and CD8--to increase (p=0.088). An activation of NK cells was observed in patients who had a low or normal pretreatment level of activation. In the 2nd group, there was a significant decrease in the CD4/CD8 ratio by the end of the treatment (p < 0.05) and increased activity of NK cells as early as 20 min after the onset of HT (p < 0.05). CONCLUSIONS Our results suggest that HT stimulates the immunity of cancer patients by several means and therefore may exhibit indirect anticancer effect. In addition, activation of NK cells by HT may be associated with improved quality of life.