Biology and therapy of prostatic cancer.

There is no effective therapy for increasing the survival of metastatic prostatic cancer. New approaches to this major disease are urgently needed. One approach is to study the biology of prostatic carcinogenesis in order to develop a treatment that prevents the initial development of clinically manifest prostatic cancer. International epidemiological data on the incidence of prostatic cancer and the data on migrant populations make this both possible and practical. For example, it should be possible to lower the incidence of clinical prostatic cancer by more than ten-fold among men in the United States. An alternative approach is to study the tumour biology of prostatic cancer to identify better methods for treating established clinical prostatic cancer. Such studies have already demonstrated that individual prostatic cancers are composed of clones of cancer cells that are phenotypically heterogeneous even before therapy is initiated. Because of this tumour cell heterogeneity, future studies should be directed towards combining androgen ablation plus chemotherapy and/or radiation early in the disease in order to affect both the androgen-dependent and the androgen-independent cancer cells present in individual prostatic cancers.