Lymph-Nodal Oligometastases from Prostate Cancer: Different Outcomes and Pattern of Relapse between Pelvic and Para-Aortic Disease

Abstract

Introduction: Lymph-nodal prostate cancer oligometastases are differently treated according to their site: pelvic are locoregional lymph-nodes, instead para-aortic lymph-nodes are considered as distant metastases. Aim of the study was a comparison between para-aortic and pelvic oligometastases treated with stereotactic body radiation therapy (SBRT). Material/methods: This is a retrospective analysis. De-novo metastatic or extra-nodal disease were excluded. Univariate and multivariate analyses were performed; pattern of recurrence was evaluated too. A propensity score matching (PSM) was applied to create comparable cohorts. Primary end-point was the progression-free survival (PFS). Secondary end-points were biochemical relapse-free survival (BRFS), ADT-free survival (ADTFS), polymetastases-free survival (PMFS), local progression-free survival (LPFS) and pattern of relapse. Results: 240 lymph-nodal oligometastases in 164 patients (127 pelvic and 37 para-aortic) were treated. Median PFS was 20 and 11 months in pelvic and para-aortic patients respectively (p=0.042). The difference was not confirmed at the multivariate analysis (p=0.06). Median BRFS was 16 and 9 months respectively in pelvic and para-aortic group (p=0.07). No statistically significant differences for ADTFS or PMFS were detected. The cumulative 5-years LPFS was 90.5%. At PSM no statistically significant differences for all the study end-points were detected. Conclusions: Patients affected by para-aortic disease might have PFS comparable to pelvic disease; local control is high in both cohorts. Our results support the use of SBRT also to para-aortic metastases.