Abstract 2346: Uptake of conservative management, and uptake of curative-intent treatment following conservative management, in low and favorable-intermediate risk prostate cancer patients.

Abstract Background Low-risk and favourable-intermediate risk prostate cancer patients are eligible for conservative management. We estimated the probability of conservative management uptake and 10-year rates of curative treatment initiation following conservative management in a prospective cohort of 2,872 health professionals diagnosed with low or favorable-intermediate risk prostate cancer. Methods The study included males with low-risk (grade group 1, stage≤cT2a, prostate-specific antigen (PSA)<10ng/ml) and favourable-intermediate risk (grade group 1, stage cT2b-cT2c or PSA 10-20ng/ml, or grade group 2, stage≤cT2a and PSA<10ng/ml) prostate cancer whom were diagnosed 1986-2019 and were participants in the Health Professionals Follow-up Study. We estimated the variation in conservative management uptake by age and calendar year at diagnosis, prostate cancer risk group, and pre-diagnostic lifestyle using Poisson regression. We estimated 10-year rates of curative treatment initiation in patients that initially received conservative management using Fine and Gray models adjusted for competing risks of lethal progression (prostate cancer death, metastasis, or initiation of hormone therapy) and other-cause death, censoring at December 2022. We assessed the variation in continuation to curative treatment with Cox models. Results The uptake of conservative management was 16% (444/2872). Conservative management was higher in older patients (1 year of additional age - Relative Risk (RR): 1.08, 95% CI: 1.06 - 1.11), in later calendar years (1 additional year - RR: 1.07, 95% CI 1.05 - 1.10)), and in neighborhoods of higher socioeconomic status (1 standard deviation rise - RR: 1.16. 95% CI 1.03 - 1.30). Uptake was lower in favorable-intermediate risk, rather than low-risk, prostate cancer (RR: 0.47. 95% CI 0.35 - 0.61). Among the 444 patients who initially received conservative management, when adjusted for competing risks of lethal progression and other-cause death, the 10-year curative treatment incidence was 22%. Patients were more likely to continue to curative treatment if they were younger at diagnosis (1 year of additional age - Hazard Ratio (HR): 0.96, 95% CI: 0.93 - 0.99) or had healthier post-diagnostic lifestyles (increase of 1 in joint measure of physical activity, BMI, and smoking, scored 0-3 - HR: 1.47, 95% CI 1.01 - 2.15). Conclusion We found age at diagnosis, calendar year at diagnosis, prostate cancer risk group, and neighborhood-level socioeconomic status to affect conservative management uptake, and age at diagnosis and post-diagnostic lifestyle to affect rates of curative treatment initiation following conservative management, in low/favorable-intermediate risk prostate cancer patients. These results could inform the clinical management of low/favorable-intermediate risk prostate cancer. Citation Format: Isaac Allen, Jane Bailey Vaselkiv, Hannah E. Guard, Sinead Flanagan, Hari Iyer, Kevin Kensler, Jaime E. Hart, Mark A. Preston, Andreas Pettersson, Keyan Salari, Edward L. Giovannucci, Adam S. Kibel, Lorelei A. Mucci, Timothy Rebbeck. Uptake of conservative management, and uptake of curative-intent treatment following conservative management, in low and favorable-intermediate risk prostate cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2026; Part 1 (Regular Abstracts); 2026 Apr 17-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2026;86(7 Suppl):Abstract nr 2346.