#1047

Pattern of care and survival outcomes in older men with localised prostate cancer in an Australian population-based cohort

S. Kim¹, T. Kang¹, J. Millar¹, W. Ong¹

¹Alfred Health, Melbourne, Australia

Introduction:

Purpose/ objectives: Active treatment for prostate cancer (PC) in older men needs to be balanced against their comorbidities and life expectancy. In this study, we evaluate the patterns of care and outcomes in older men with PC in an Australian population-based cohort.

Material and methods:

Material/ methods: We included men aged ≥70 years with localised PC in the Victorian statewide Prostate Cancer Outcome Registry (PCOR-Vic) between 2008 and 2022. The primary outcomes were initial management (active treatment with surgery/ radiotherapy within 12 months vs observation) and survival outcomes. Multivariable logistic regressions were used to identify factors associated with active treatment, and multivariable Cox regressions and Fine-Gray models were used to evaluate factors associated with overall survival (OS) and prostate cancer specific mortality (PCSM), adjusting for covariables of interest.

Results:

Results: There were 10,517 men included in the study, 9,063 (86%) aged 70-79 years, and 1434 (14%) aged ≥80 years. There were 1,471 (14%), 5,374 (51%) and 3,672 (35%) with low-risk (LRPC), intermediate-risk (IRPC) and high-risk (HRPC) disease respectively. 7,249 (69%) men received active treatment – 6,613 (73%) in men aged 70-79 years, and 636 (44%) in men aged ≥80 years. The use of active treatment increased over time, from 63% in 2008-2010 to 71% in 2020-2022 (P-trend<0.001). In multivariable analyses, increasing age, being diagnosed in public institutions and earlier year of diagnosis were independently associated with reduced likelihood of active treatment. The median follow-up for the cohort was 5.7 years (IQR: 3.6-8.4 years). There were 2,172 (21%) men who died, of which 361 (3%) were PCSM. For men with IRPC with active treatment vs observation, 5-year OS were 94% (95%CI=93-95%) and 87% (95%CI=85-89%) (P<0.001), and 5-year PCSM were 0.5% (95%CI=0.3-0.9%) and 1.0% (95%CI=0.5-1.8%) (P=0.2), respectively. For men with HRPC with active treatment vs observation, 5-year OS were 88% (95%CI=87-89%) and 63% (95%CI=59-67%) (P<0.001), and 5-year PCSM were 4.1% (95%CI=3.4-5.0%) and 10.8% (95%CI=8.2-14.3%) (P<0.001), respectively. In multivariable analyses, active treatment was associated with OS benefits for IRPC (HR=0.70;95%CI=0.61-0.82;P<0.001) and HRPC (HR=0.61;95%CI=0.52-0.7;P<0.001), but no differences in PCSM for both IRPC (sHR=1.26;95%CI=0.75-2.11;P=0.4) and HRPC (sHR=0.85;95%CI=0.60-1.19;P=0.3).