OBJECTIVE: To investigate how much Gleason pattern 3 cancer the prostate biopsy specimens may contain without an increased risk of undetected more aggressive cancer, compared with the risk for cancers fulfilling the National Comprehensive Cancer Network (NCCN) criteria for very low risk prostate cancer.
SUBJECTS AND METHODS: We identified 1,286 men aged < 70 years in the National Prostate Cancer Register of Sweden who underwent primary radical prostatectomy for stage T1c or T2 prostate cancer with Gleason pattern ≤ 3 only, prostate-specific antigen < 10 ng/mL and PSA density < 0.15 ng/ml/cc. The association between the extent of cancer in the biopsies (the number and proportion of positive cores and the total cancer length in the cores in mm) and the likelihood of Gleason pattern 4-5 in the prostatectomy specimen was analysed with logistic regression.
RESULTS: Overall, 438 (34%) of the 1,286 men had Gleason pattern 4-5 in the prostatectomy specimen. Increasing number and proportion of positive biopsy cores as well as increasing biopsy cancer length were both significantly associated with increased risk of upgrading at radical prostatectomy in univariable analysis, but in multivariable analysis only biopsy cancer length remained significant. The 684 men with stage T1c and < 8 mm cancer had similar risk of upgrading regardless of whether the number of positive biopsy cores was 1-2 or 3-4 (28% versus 27% risk); upgrading was more common among the remaining men (40%, p < 0.01).
CONCLUSIONS: Men younger than 70 years with stage T1c prostate cancer and 3-4 biopsy cores with Gleason pattern 3 are not more likely to have undetected Gleason pattern 4-5 cancer than men with 1-2 cores with cancer, provided that the total biopsy cancer length is < 8 mm. We propose that the definition of very low risk prostate cancer is widened accordingly.
Bratt O, Folkvaljon Y, Loeb S, Klotz L, Egevad L, Stattin P. Are you the author?
Nuffield Department of Surgical Sciences, University of Oxford, Oxford, United Kingdom; Department of Urology, Helsingborg Hospital, Lund University, Sweden.
Reference: BJU Int. 2014 Jul 23. Epub ahead of print.