Failure of Ploidy and Proliferative Fraction to Predict Long-Term Outcome After Prostatectomy

Historically, ploidy and S phase percentage appeared to be promising predictors for prostate cancer recurrence. Lack of uniformity and consistency hampered their development. We evaluated ploidy and S phase for prostate cancer death in a cohort of patients with long-term follow-up.

We identified 127 patients that had ploidy and S phase determined at the time of their radical prostatectomy for prostate cancer. With 15 years of follow-up, we determined the risk of biochemical failure and risk of death from prostate cancer. We correlated the S phase and ploidy findings with standard pathology findings.

A total of 107 (84%) had diploid and 20 (16%) had non-diploid cancers. The median S phase was 6.6%. There was no correlation of ploidy (P = 0.472) or S phase with preoperative PSA or Gleason score. On univariate analysis, EPE, margin positivity, seminal vesicle involvement, lymph node involvement, high Gleason score and PSA > 10 ng/mL were all predictive of biochemical failure. Ploidy and S phase were not. For prostate cancer death, only Gleason score was predictive.

With long-term follow-up in our cohort, Gleason score was predictive of prostate cancer death. Ploidy and S phase were not predictive for biochemical failure or prostate cancer mortality.