8,040 men presenting with bone metastasis between 2010-2013 from the SEER database formed the study cohort. A Fine and Gray’s competing risks model was used to generate hazards ratios (HR) to identify predictors of PCSM. Kaplan-Meier analysis using log-rank test was used to assess PCSM stratified by extent of metastasis.
There were 2,497 men (31.1%) experiencing PCSM and 5,543 men (68.9%) without PCSM (n=643 dead of other causes; n=4,900 alive) over a median follow-up of 35mo (IQR: 34-37). Patients with PCSM were older, unmarried, more likely to live in Southeast US, have biopsy Gleason Group (bGG) 5 disease or have no prostate biopsy, and have concomitant PCa brain, liver, and lung metastasis at diagnosis, compared to patients without PCSM. Competing risks modeling identified older age, non-black/white race, unmarried status, living in Southeast US, higher PSA, with a biopsy Gleason score of 4 or above, or with having no prostate biopsy, and having brain, liver and lung metastasis at diagnosis as predictive of PCSM. Increasing volume of visceral metastasis with bone metastasis lead to worse survival vs bone metastasis alone, with median time to PSCM of 27 months for bone + lung metastasis (HR 1.35, 95%CI 1.13-1.62), 15 months for bone + liver metastasis (HR 2.28, 95%CI 1.81-2.86), and 11 months for bone + lung + liver metastasis.
Men presenting with PCa-bone metastatic disease may have aggressive tumor biology and are at risk of PCSM in <3 years. Patients with aggressive prostate disease presenting with bone and concomitant visceral metastasis should be considered for early, aggressive systemic therapy and/or clinical trials.
Presented by: Zachary Klaassen, Toronto, Canada
Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre, @GoldbergHanan, at the 18th Annual Meeting of the Society of Urologic Oncology, November 29-December 1, 2017 – Washington, DC