Racial disparities in the care of patients with advanced prostate cancer: an analysis of patient-reported outcome and experience measures

Abstract

In the US, an estimated 120,000 individuals are living with advanced prostate cancer, defined as metastatic hormone sensitive prostate cancer (mHSPC) or castration resistant prostate cancer (CRPC). Black individuals experience the most significant advanced prostate cancer burden with over double the age-adjusted prevalence and mortality compared to White individuals. Previous studies on the experience of individuals with advanced prostate cancer were typically conducted in primarily White populations participating in randomized controlled trials of disease-directed therapies. With numerous clinical and therapeutic advances for advanced prostate cancer in the past decade, there is a need for a contemporary analysis of the patient experience with a specific focus on identifying unmet needs in Black patients. In Chapter 1, we used data from 701 participants in the International Registry for Men with Advanced Prostate Cancer (IRONMAN) to investigate racial differences in experience with the healthcare system at the time of a new diagnosis of advanced prostate cancer. We estimated prevalence differences by self-reported race for six questions from the Cancer Australia National Cancer Control Indicators about patient information and communication regarding treatment, patient coordination and integration of care, and respect for patient preference. We found that most participants reported a high quality of care, with Black participants generally reporting higher care quality than White participants. Our study suggests that there are other dimensions of the patient experience that are not captured by this survey, and investigating the interpersonal aspects of care will be important to more fully understand the experience of the healthcare system in this population. In Chapter 2, we used data from 879 IRONMAN participants to investigate racial differences in quality of life at study enrollment and throughout the first year on study. We fit linear mixed effects models of 15 functioning and symptom scales from the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire. We found that Black participants tended to have poorer quality of life at study enrollment compared to White participants and that quality of life decreased over the first year on study with minimal differences in trajectory between Black and White participants. Our study identifies domains of quality of life to be further studied and intervened upon to meaningfully improve the overall survivorship experience. In Chapter 3, we used data from 879 IRONMAN participants to investigate racial differences in pain at study enrollment and the association between longitudinal pain trajectories and survival. Participants responded to questions on interference of pain with daily activities, average pain rating, worst pain rating, and presence of bone pain at study enrollment and every 3-6 months throughout up to 5 years of follow up. We fit Cox proportional hazards models and longitudinal survival models to estimate the association between each pain scale and mortality. We found that Black participants had worse pain at enrollment compared to White participants and that higher pain at enrollment and longitudinally for each pain scale was associated with higher mortality after adjusting for measures of disease burden. Our study highlights the need for a deeper understanding of the different facets of pain in advanced prostate cancer populations to determine points for intervention and improvement of quality of life. Taken together, these studies illuminate the experience of individuals living with advanced prostate cancer. We found numerous quality-of-life detriments in this patient population, especially in Black participants, that can impact both wellbeing and long-term survival from prostate cancer. Using descriptive studies to assess patient experience and quality of life, this work lays the foundation for further investigation into mechanisms underlying the racial disparities that we identified. This work provides a starting point for patient-centered prostate cancer research to identify ways to improve quality of life and the overall survivorship experience for individuals living with advanced prostate cancer, particularly for Black individuals who face the highest morbidity and mortality from the disease.