Marital status, living arrangement, and overall survival among individuals with advanced prostate cancer in the IRONMAN cohort

Abstract Background: More than 100,000 individuals in the United States are survivors of advanced prostate cancer, defined as metastatic hormone sensitive (mHSPC) or castration resistant prostate cancer (CRPC). This growing, vulnerable population could be uniquely susceptible or responsive to factors that are associated with overall survival. We investigated the associations of marital status and living arrangements with overall survival among individuals with advanced prostate cancer in the International Registry for Men with Advanced Prostate Cancer (IRONMAN). Methods: We included 2,347 men (ages 40-96 years, median 70 years) with advanced prostate cancer recruited between 2017 and October 2022. Cox proportional hazards models estimated adjusted hazard ratios (adjusted HR) and 95% confidence intervals (CI) for the associations between marital status (married vs. not married), living arrangement (living alone vs. not living alone) and all-cause mortality, mutually adjusting for marital status and living arrangement and potential confounders (disease state [mHSPC vs. CRPC], country of enrollment, age at enrollment, race, education, employment status, smoking status, family history of prostate cancer, prostate specific antigen level at enrollment, and Gleason score). We conducted stratified analyses by disease state (mHSPC vs. CRPC), age (<70 vs. ≥70 years), and country of enrollment (North America vs. others). Results: This study included 1524 (65%) participants with mHSPC and 809 (35%) with CRPC. 1690 (77%) were married and 338 (16%) lived alone. Over the follow-up period (maximum: 52 months, median: 6 months, IQR: 13 months), we observed 451 deaths, with 313 deaths among married individuals and 59 deaths among those who lived alone. Overall, married individuals had better survival compared to those not married (adjusted HR: 0.52; 95% CI 0.35, 0.78), while those living alone had better survival compared to those not living alone (adjusted HR: 0.48; 95% CI: 0.29, 0.80). The protective association between being married and survival is stronger among those with mHSPC (adjusted HR: 0.42; 95% CI: 0.24, 0.71) compared to those with CRPC (adjusted HR: 0.72; 95% CI: 0.35, 1.49) and stronger among those with ages 70 or older (adjusted HR: 0.43; 95% CI: 0.25, 0.74) compared to those younger than 70 (adjusted HR: 0.71; 95% CI: 0.36, 1.43). Conclusion: Being married was associated with better survival among advanced prostate cancer survivors. While living alone was also associated with better survival, this finding should be interpreted with caution as there may be residual confounding by socioeconomic status or physical functioning. Citation Format: Naiyu Chen, Colleen B. McGrath, Caroline I. Ericsson, Jane B. Vaselkiv, Michelle O. Sodipo, Emily M. Rencsok, Konrad H. Stopsack, Daniel J. George, Karen A. Autio, Dana E. Rathkopf, Kathryn L. Penney, Lorelei A. Mucci. Marital status, living arrangement, and overall survival among individuals with advanced prostate cancer in the IRONMAN cohort. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6489.