New concepts in the treatment of stage D1 adenocarcinoma of the prostate. Stage D1 disease will be encountered in 20 per cent of patients by those who treat prostate cancer. There is marked heterogeneity among cancers discovered at this stage, with 5-year disease-free survival rates ranging from 0 to 95 per cent. Generally, when prostate cancer has escaped the confines of the gland, metastasis occurs, and widespread systemic disease prevails. Any significant chance for long-term cure will then depend on systemic therapy. From maturing data in retrospective reviews, preliminary data from prospective trials, and recent well-conducted animal studies, chemotherapy and hormonal deprivation appear most effective when tumor volumes are the smallest. This evidence supports the removal of all cancer possible and the early institution of systemic treatment. Caution must be exercised in extrapolating the aforementioned evidence to include cases of more extensive prostate cancer (i.e., patients with bulky pelvic or retroperitoneal disease, distant metastasis, or significant elevation of serum markers). It is doubtful that "debulking" with removal of the prostate and lymph nodes will provide any justifiable advantages in these patients. Whether removal of the prostate affords any local palliative benefit is an issue for debate. Certainly, the primary tumor, if left untreated, will progress locally and cause symptoms necessitating further procedures in more than half these patients, whereas the incidence of local recurrence and the adverse effects of these recurrences in patients with D1 disease after radical prostatectomy and adjuvant therapy is less than 10 per cent. Surgical refinements coupled with acceptably low morbidity now associated with radical prostatectomy have led some authors to endorse the palliative benefits of removing the primary tumor in selected patients. The purpose of this article is not to endorse or disparage the aggressive treatment of patients with stage D1 prostate cancer. The evidence suggests that if long-term survival is the endpoint used to compare treatment groups, then to date no treatment option offers significant advantages. On the contrary, if progression rates or disease-free survival are compared, then cytoreductive surgery and early systemic adjuvant treatment (testosterone deprivation or chemotherapy) provides significant advantages for selected patients with stage D1 disease. Although ploidy analysis, receptor mapping, and oncogene assays are promising, today, there is no practical way to identify patients who will benefit most from multimodality treatment approaches.(ABSTRACT TRUNCATED AT 400 WORDS). 