De-differentiation with time in prostate cancer and the influence of treatment on the course of the disease.

Summary— There is little information on histological changes in prostate cancer during the course of the disease. We have studied 74 patients with carcinoma of the prostate who required 2 transurethral resections of the prostate (mean interval between resections 2.4 years). They constituted 18.4% of all patients with carcinoma of the prostate presenting to our clinic between January 1978 and April 1988. All tumours were staged by conventional methods and graded using the Gleason system. The Gleason sum score in those patients with tumour in both specimens increased in 49, remained constant in 12 and decreased in 7. Within this group were 34 patients who were treated expectantly. The mean Gleason sum scores in this group increased, with a concomitant increase in local tumour stage and development of metastases. Although this was not a randomised trial, there was no significant difference in survival between patients having “deferred” management and those treated immediately, either from time of diagnosis or from time of second resection. There was, however, a significant difference in the time to second resection, with the “deferred” group requiring repeat resection on average 1 year earlier. This study confirmed the concept of tumour de-differentiation with time and showed that this phenomenon occurs in both treated and untreated tumours. Although overall survival was not influenced by the type of initial therapy or its timing, local progression, as assessed by the need for further TURP, occurred earlier in those not receiving immediate therapy.