Long-term Outcomes of Salvage Lymph Node Dissection for Nodal Recurrence of Prostate Cancer After Radical Prostatectomy: Not as Good as Previously Thought.

Overview

abstract

BACKGROUND: Long-term outcomes of patients treated with salvage lymph node dissection (sLND) for nodal recurrence of prostate cancer (PCa) remain unknown. OBJECTIVE: To investigate long-term oncological outcomes after sLND in a large multi-institutional series. DESIGN, SETTING, AND PARTICIPANTS: The study included 189 patients who experienced prostate-specific antigen (PSA) rise and nodal-only recurrence after radical prostatectomy (RP) and underwent sLND at 11 tertiary referral centers between 2002 and 2011. Lymph node recurrence was documented by positron emission tomography/computed tomography (PET/CT) scan using either ¹¹C-choline or ⁶⁸Ga prostate-specific membrane antigen ligand. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary outcome of the study was cancer-specific mortality (CSM). The secondary outcomes were overall mortality, clinical recurrence (CR), biochemical recurrence (BCR), and androgen deprivation therapy (ADT)-free survival after sLND. The probability of freedom from each outcome was calculated using Kaplan-Meier analyses. Cox regression analysis was used to predict the risk of prostate CSM after accounting for several parameters, including the use of additional treatments after sLND. RESULTS AND LIMITATIONS: At long term, 110 and 163 patients experienced CR and BCR, respectively, with CR-free and BCR-free survival at 10 yr of 31% and 11%, respectively. After sLND, a total of 145 patients received ADT, with a median time to ADT of 41 mo. At a median (interquartile range) follow-up for survivors of 87 (51, 104) mo, 48 patients died. Of them, 45 died from PCa. The probabilities of freedom from cancer-specific and all-cause death at 10 yr were 66% and 64%, respectively. Similar results were obtained in sensitivity analyses in patients with pelvic-only positive PET/CT scan, as well as after excluding men on ADT at PET/CT scan and patients with PSA level at sLND higher than the 75th percentile. At multivariable analyses, patients who had PSA response after sLND (hazard ratio [HR]: 0.45; p = 0.001), and those receiving ADT within 6 mo from sLND (HR: 0.51; p = 0.010) had lower risk of death from PCa. CONCLUSIONS: A third of men treated with sLND for PET-detected nodal recurrence of PCa died at long term, with PCa being the main cause of death. Salvage LND alone was associated with durable long-term outcomes in a minority of men who significantly benefited from additional treatments after surgery. Taken together, all these data argue against the use of metastasis-directed therapy alone for patients with node-only recurrent PCa. These men should instead be considered at high risk of systemic dissemination already at the time of sLND. PATIENT SUMMARY: We assessed long-term outcomes of patients treated with salvage lymph node dissection (sLND) for node-recurrent prostate cancer (PCa). In contrast with prior evidence, we found that the majority of these men recurred after sLND and eventually died from PCa. A significant survival benefit associated with the administration of androgen deprivation therapy after sLND suggests that sLND should be considered part of a multimodal approach rather than an exclusive treatment strategy.