Impact of positive surgical margins on biochemical recurrence and metastases after radical prostatectomy.

Abstract

To evaluate the impact of the presence, extent and location of positive surgical margins (PSMs) on the risk of biochemical recurrence (BCR) and metastases in a nationwide cohort of patients who underwent radical prostatectomy (RP) and had 5 years of follow-up. All patients diagnosed with prostate cancer in the Netherlands between October 2015 and April 2016 who underwent RP were included in a prospective cohort. Data on these patients from the Netherlands Cancer Registry and the PALGA pathology registry were analysed. BCR was defined as a prostate-specific antigen (PSA) level ≥0.1 ng/mL >28 days after RP. Exclusion criteria were (neo)adjuvant treatment, pN1 disease, and salvage therapy initiated at PSA <0.1 μg/L. Multivariable Cox regression analyses were performed to evaluate the impact of PSM presence, extent and location on the risk of BCR and metastases. Of 998 patients, 311 (31%) had PSMs (median length 5.0 mm). Over 5 years of follow-up, 36% of patients experienced BCR and 11% developed metastases. PSMs ≥3 mm were associated with a significantly increased risk of BCR (hazard ratio [HR] 2.04, 95% confidence interval [CI] 1.58-2.64; P < 0.001) and metastases (HR 2.12, 95% CI 1.21-3.74; P = 0.009) compared to negative surgical margins. By contrast, PSMs <3 mm and PSM location did not significantly increase the risk of BCR or metastases. Our study showed that PSMs ≥3 mm appear to be independently associated with an increased risk of BCR and metastases after RP. Therefore, avoiding or limiting the extent of PSMs during RP remains essential.