Histological and immunohistochemical changes after transurethral balloon laser hyperthermia in the canine prostate

Transurethral balloon laser hyperthermia (TUBAL-H) for the prostate was performed in a canine model. Eleven normal and hyperplastic prostates were heated at between 40 to 45 degrees C for 30 min. Compared to the pretreatment weight, the prostatic weight significantly increased immediately after treatment and significantly decreased at 4 weeks later, but was not significantly different after 8 weeks. Histologically, shedding of epithelial cells was observed immediately after treatment, although, coagulonecrotic tissue was not seen. After 8 weeks, atrophic changes of epithelial cells were observed at the inner portion of the prostate. By immunohistochemical analysis, epithelial cells expressing apoptosis related antigen (Ley) were observed at the inner portion of the prostate from immediately after treatment until 4 weeks later. The atrophic epithelia and the expression of apoptosis in the prostate gland were pathological changes induced by TUBAL-H. From the present data, it is suggested that TUBAL-H combined with radiation or administration of anti-cancer drugs may be effective for prostate cancer.