Patrick Craig Walsh

The dramatic decline in observed prostate cancer mortality after the introduction of prostate-specific antigen (PSA) screening provides compelling evidence in support of testing. Pinsky et al. (March 30 issue)¹ state that from the late 1980s to the present, the prostate cancer mortality rate fell 45%. This underestimates what really happened. Because PSA testing did not become widespread until 1990, prostate cancer mortality rates continued to rise past the late 1980s. Recently, the American Cancer Society reported that the prostate cancer mortality rate fell 51% from 1993 to 2014.² Furthermore, Pinsky et al. suggest that this finding is equivocal because of “likely confounding by increasingly effective systemic therapies.” It has been shown that there was no improvement in overall or cause-specific survival among men with metastatic disease who presented between 1988 and 2009.³ What systemic therapies administered between 1993 and 2014 were responsible for the observed decline in mortality?

5020 Background: The importance of local treatment in oligometastatic prostate cancer (OPC) is unknown. Stereotactic ablative radiotherapy (SABR) is highly focused, high-dose radiation that is well suited for treatment of oligometastases. Here we report on the safety and preliminary clinical outcomes of SABR in a modern cohort of OPC men. Methods: Eighty four men who satisfied criteria of OPC diagnosed on imaging underwent consolidative SABR were then followed prospectively on our IRB approved registry by our GU multidisciplinary team. We collected demographic, clinical, toxicity and efficacy information. We examined the first 66 men in this preliminary report to allow for a minimum of 4.5 months follow-up. SABR was delivered in 1-5 fractions of 5-18 Gy. Kaplan-Meier method was used to assess local progression-free survival (LPFS), biochemical progression-free survival (bPFS; PSA nadir+2), distant progression free survival (DPFS), ADT-free survival (ADT-FS) and time-to-next intervention (TTNI). Results: Of the 66 OPC patients analyzed, 25 (38%) men presented as synchronous OPC and the remaining 41 had recurrent OPC. Median and mean follow-up was 61 and 66 weeks, respectively. Patient and disease factors as listed in the Table. Crude Grade 1 and 2 acute toxicities were 36% and 11%, respectively, with no Grade > 2 toxicity. SABR was delivered to 134 metastases: 89 bone (66%), 40 nodal (30%) and 5 (4%) visceral metastases. Overall LPFS at 1-year was 92%. The bPFS and DPFS at 1-year were 69% and 69%, respectively. Median TTNI was not reached yet. Of the 18 men with hormone sensitive prostate cancer who had their ADT deferred, 11/18 (56%) remain free of disease following SABR (1-year ADT-FS was 78%) and in 17 castration resistant men, 11 had > 50% PSA declines with 1-year TTNI of 30% with a median of 45 weeks. Conclusions: Consolidative SABRfor OPCis feasible and well tolerated. The preliminary clinical outcomes in our series is limited by heterogeneity and size but our data suggests that this approach is worthy of further prospective study. [Table: see text]