Surveillance or metastasis-directed therapy for oligometastatic prostate cancer recurrence (STOMP): Five-year results of a randomized phase II trial.
Piet Ost, Dries Reynders, Karel Decaestecker, Valérie Fonteyne, Nicolaas Lumen, Aurélie De Bruycker, Bieke Lambert, Louke Delrue, Renée Bultijnck, Els Goetghebeur, Geert Villeirs, Kathia De Man, Filip Ameye, Ignace Billiet, Steven Joniau, Friedl Vanhaverbeke, Gert De Meerleer
Abstract
10 Background: Multiple randomized phase II trials suggest that metastasis-directed therapy (MDT) for oligometastatic prostate cancer (PCa) improves progression-free survival, but the majority of trials lack longer follow-up. We present the updated 5-year results from the STOMP-trial. Methods: In this multicentre, randomised, phase II study, asymptomatic PCa patients were eligible in case of a biochemical recurrence following primary PCa treatment with curative intent and presenting with up to 3 extracranial on choline PET-CT and a serum testosterone levels > 50 ng/ml. Patients were randomly assigned (1:1) to either surveillance or MDT of all detected lesions. Randomisation was balanced dynamically on two factors: PSA doubling time (≤3 vs. > 3 months) and nodal vs non-nodal metastases. The primary endpoint was androgen deprivation therapy (ADT)-free survival. Castrate resistant prostate cancer-free survival (CRPC) was a secondary endpoint. Tests were performed two-sided; p values less than 0.20 were deemed significant. Results: The 5-year ADT-free survival was 8% for the surveillance group and 34% for the MDT group (Figure 1, hazard ratio 0.57 [80% CI: 0.38-0.84], log-rank p = 0.06). There was no significant difference in effect for the different stratification factors (interaction test). The 5-year CRPC-free survival was 53% for the surveillance group and 76% for the MDT group (hazard ratio 0.62 [80% CI: 0.35−1.09]; log−rank p = 0.27). At a median follow for survival of 5.3 years (IQR 4.3-6.3), the 5-year overall survival was 85%, with 6 out of 14 deaths attributed to prostate cancer. Conclusions: The updated STOMP trial outcomes confirm the earlier reported significant difference in ADT free survival in favor of the MDT group compared to surveillance. Prostate-cancer related mortality is low within the first 5 years of diagnosis of oligorecurrent prostate cancer. Clinical trial information: NCT01558427.