Influence of DNA ploidy and adjuvant treatment on progression and survival in patients with pathologic stage T3 (PT3) prostate cancer after radical retropubic prostatectomy

Abstract

Objectives: To determine whether adjuvant treatment (AT: hormonal or radiation) affects outcome in pathologic Stage T3 (pT3) prostate cancer when analyzed according to DNA ploidy.

Methods: The predictive value of nuclear DNA ploidy and AT on clinical and prostate-specific antigen (PSA) progression and on overall and cause-specific survival after radical retropubic prostatectomy was assessed in 894 patients with pT3 prostate cancer.

Results: Mean follow-up was 6.7 years (range, 0.3 to 20). Mean age was 66 years (range, 39 to 79). Six hundred sixty patients (74%) had no immediate AT, 131 (15%) had early adjuvant radiotherapy (ART), and 103 (12%) had early adjuvant orchiectomy (AHT). DNA diploid tumors were found in 445 patients (52%), tetraploid tumors in 346 (41%), and aneuploid tumors in 59 (7%). DNA ploidy was a significant (P < 0.05) prognostic indicator for clinical systemic progression-free survival. With PSA progression (more than 0.2 ng/mL) as an endpoint, ploidy was an even more powerful predictor for outcome (P = 0.004). Use of early AHT or ART was associated with decreased overall clinical progression for diploid and nondiploid tumors (P < 0.001 and P < 0.001, respectively). With respect to PSA progression, ART and AHT were equally effective and superior to no AT only in patients with diploid tumors. However, in patients with nondiploid tumors, only AHT appeared to have improved PSA progression-free survival (P < 0.001) over ART or no AT, which are similar in outcome.

Conclusions: In the present nonrandomized study, AHT was as effective as ART for all endpoints except for PSA more than 0.2 ng/mL progression, for which it appeared to be superior to ART for patients with nondiploid tumors.