Correlation of pre-treatment transurethral resection and prognosis in patients with stage C carcinoma of the prostate treated with definitive radiotherapy--RTOG experience

Four hundred and ninety-four patients with clinical Stage C carcinoma of the prostate, who were entered onto a phase III RTOG study, have been analyzed as to the potential effect of the pre-treatment transurethral resection (TUR) of the tumor. Treatment consisted of definitive irradiation to the prostate (6500-7000 cGy) and regional lymphatics (4500-5000 cGy). A total of 202 patients underwent pre-treatment TUR. This population was compared with the remaining 292 patients as to the rate of locoregional failure, incidence of distant metastases, disease-free survival, and survival. The TUR population fared significantly worse for all four end-points. To account for uneven distribution of recognized prognostic factors the results were then adjusted using stratified Mantel-Haenszel tests. The stratification process resulted in a reduced level of significance in the differences between the two populations. However, a trend toward a higher incidence of distant metastases could be observed within most strata. The trend was most pronounced in subpopulations characterized by Gleason score 6-7 and normal serum acid phosphatase (SAP). For the population characterized by Gleason score 6-10 and normal SAP, the differences in the incidence of distant metastases retained statistical significance. Whether these findings are secondary to tumor dissemination during TUR or are due to incompletely identified selection biases remains to be demonstrated in future (prospective) studies.