Presentation Authors: Nazareno Suardi*, Giorgio Gandaglia, Daniele Robesti, Simone Scuderi, Francesco Barletta, Paolo Dell'Oglio, Elio Mazzone, Marco Bandini, Massimo Freschi, Armando Stabile, Milan, Italy, Shahrokh Shariat, Vienna, Austria, Vincenzo Mirone, Nicola Longo, Naples, Italy, Francesco Soria, David D'Andrea, Vienna, Austria, Roberta Lucianò, Umberto Capitanio, Nicola Fossati, Francesco Montorsi, Alberto Briganti, Milan, Italy
Introduction: Positive surgical margins (PSM) are associated with an increased risk of biochemical recurrence (BCR) in prostate cancer (PCa) patients undergoing radical prostatectomy (RP). Nonetheless, not all patients with PSM ultimately experience clinical recurrence or cancer-specific mortality (CSM) given also the impact of other cause mortality (OCM).
Methods: Overall, 5388 PCa patients treated with RP between 2000 and 2017 were identified. Patients who did not receive adjuvant therapies and with PSMs (n=913; 17%) were then identified. Of these, 615 (67%) who had available details on total length (mm) and focality (single vs. multiple). Unfavourable PSM was defined as a margin â‰¥3 mm or multifocal. CSM was defined as death from PCa. OCM was defined as death from other causes. Competing-risk analyses generated cumulative-incidence CSM and OCM rates according to PSM and their characteristics. The same analyses were repeated after stratifying patients in two groups: favorable (pT2 and pathologic grade group 1-3 and pN0/x) vs. adverse pathologic characteristics (pT3b/4 and/or pathologic grade group 4-5 and/or pN1). Multivariable competing-risks regression models assessed the effect of PSM on CSM after accounting for OCM.
Results: Median PSM length was 2 mm and 225 (36%) patients had multifocal margins. Median follow-up was 70 months and 22 and 156 patients experienced CSM and OCM. The 10-year CSM- and OCM-rates were 1.5 and 5%. The 10-year CSM rates were 1.4 vs. 0.1 vs. 6% after stratifying patients according to PSM status (no vs. favourable vs. unfavourable PSM; P < 0.001). When considering patients with favourable pathology, no differences were observed in CSM rates after stratifying patients according to PSM characteristics (namely, length >3 mm and multi-focality). When considering men with adverse pathologic features, the 10-year CSM rates were 0.1 vs. 19% in men with favourable vs. unfavourable PSM (P=0.03). This was confirmed at multivariable competing-risks regression analyses, where unfavourable PSM increased the risk of CSM exclusively in men with adverse pathological features (Hazard ratio: 4.27; P=0.04).
Conclusions: Unfavourable PSM increased the risk of dying from PCa after adjusting for the risk of OCM only in men with adverse pathologic characteristics. While these data should reassure regarding the oncologic safety of RP without adjuvant therapies in men with favourable PSM, men with a multi-focal PSM or a length â‰¥3 mm and concomitant aggressive disease should be considered for adjuvant therapies.