Does repeat biopsy affect the prognosis of patients with prostate cancer treated with radical prostatectomy? Analysis by the number of cores taken at initial biopsy.

UNLABELLED: Study Type - Therapy (case series) Level of Evidence 4 What's known on the subject? and What does the study add? To date, studies to evaluate clinical significance of prostate cancer detected on repeat biopsy in patients who underwent radical prostatectomy have yielded inconsistent results. The present study confirms that prostate cancer diagnosed after repeat biopsies is related to better pathological outcomes after radical prostatectomy, but not predictive of biochemical recurrence. Additionally, we find that the number of cores taken at initial biopsy do not affect the association between the number of previous biopsies and the prognosis.
OBJECTIVE: To determine whether repeat prostate biopsies are associated with more favourable prognoses compared with diagnosis at initial biopsy in patients who undergo radical prostatectomy for prostate cancer and to determine if this association is affected by the number of cores taken at initial biopsy. PATIENTS AND METHODS: We reviewed 1147 patients with prostate cancer from 1991 to 2008. Patients were stratified into two groups by the number of biopsies before diagnosis (initial biopsy vs repeat biopsy: at least two biopsies). The effects of several variables on pathological outcomes and biochemical recurrence-free and systemic progression-free survivals were assessed.
RESULTS: Of the 1147 patients, 1064 (92.8%) were diagnosed with cancer at first biopsy and 83 (7.2%) at repeat biopsy. Compared with patients diagnosed at initial biopsy, those diagnosed at repeat biopsies were more likely to have a lower clinical stage (cT1c: 79.5% vs 55.5%, P < 0.001) and organ-confined tumours (78.3% vs 61.3%, P= 0.003), but there was no significant difference in initial biopsy core number (8.3 vs 8.7, P= 0.373). Five-year biochemical recurrence-free and progression-free survival rates did not show significant differences between the two groups (88.8% vs 82.2%, P= 0.078; 100.0% vs 96.5%, P= 0.105, respectively), and these results were not affected by the number of cores taken at initial biopsy.
CONCLUSIONS: Although prostate cancer diagnosed after repeat biopsies was related to better pathological outcomes after radical prostatectomy, the number of previous biopsies did not predict disease recurrence. Moreover, the number of cores taken at initial biopsy did not affect these associations.