Kinetic evaluation of the effect of LHRH analog on prostatic cancer using transrectal ultrasonotomography.

The size of the prostate was measured in 11 patients with the prostatic cancer by means of transrectal ultrasonotomography after LHRH analog ([Ser(Bu)6] LHRH) treatment. Prostate volume changed parallel to serum testosterone (T) level and decreased by 17-62% compared with baseline after LHRH analog treatment for 4 months. Two different patterns were observed for the change in prostatic volume. Type A expanded transiently and then decreased gradually, while type B decreased continuously from the beginning with no expansion. After treatment for 4 months, the prostatic volume of type A was significantly less than that of type B. It is suggested that prostatic cancer showing a type A regression curve may be more sensitive to T, resulting in a better prognosis than type B.