Non-apical positive surgical margins after radical prostatectomy for pT2 prostate cancer is associated with the highest risk of recurrence.

BACKGROUND AND
OBJECTIVE: To investigate how location of positive surgical margins (PSM) in pT2 tumors affect the risk of biochemical recurrence (BR).
METHODS: The study includes 1,133 consecutive patients from 1995 until end of 2011, who had organ-confined disease (pT2) following RP. The location of PSM was stratified into apical and non-apical. BR was defined as the first PSA ≥ 0.2 ng/ml after RP. Risk of BR was analyzed with Kaplan-Meier and Cox regression analysis.
RESULTS: Median follow-up was 3.6 years (range: 0.5-15.5 years). The overall pT2 PSM rate was 26.3%. Overall, a pT2 with PSM had a 3.1-fold increased risk of BR compared to margin negative patients. Patients with pT2 apical and non-apical PSM had a 5-year biochemical recurrence-free survival of 84.9% (95% CI: 77.6-92.2%) and 78.6% (95% CI: 71.3-85.9%), respectively. In multivariate analysis, pT2 apical and non-apical PSM was individually associated with a 2.2- and 3.8-fold increased risk of BR compared to margin negative patients.
CONCLUSION: In our cohort the location of pT2 PSM was associated with time to BR, that is, patients with non-apical pT2 PSM endured the highest risk of BR compared to apical PSM. This may indicate that not all patients with pT2 PSM should be offered adjuvant therapy.