Investigators have documented geographic variation in the risk of being diagnosed with advanced prostate cancer (PCa) among Medicare beneficiaries aged 70 years or older, according to a report published in Clinical Medicine Insights: Oncology. The finding suggests that where a man lives may need to be considered in preventive health strategies.

After adjusting for individual and county-level characteristics, the predicted proportions of advanced PCa diagnoses across 158 counties ranged from 3% to 15%, according to investigators. Rural location and low health services supply (HSS) are among the factors associated with a higher risk of receiving an advanced PCa diagnosis.

“Current guidelines for prostate cancer screening are based primarily on the results of clinical trials that do not consider how a patient’s surroundings such as availability of health care services and area-level socioeconomic characteristics might impact prostate cancer screening and mortality outcomes in older men in the US,” lead author Jinani Jayasekera, MS, PhD, of the Lombardi Comprehensive Cancer Center at Georgetown University Medical Center in Washington, DC, told Renal & Urology News.

The goal of the current study was to better understand how area-level characteristics of socioeconomic status (SES), HSS, and individual preventive behavior might influence the incidence of advanced stage PCa among Medicare-eligible elderly men, Dr Jayasekera said.

She and her colleagues were not surprised by the results showing that counties with poor SES and HSS have a greater probability of advanced PCa diagnoses. “However, as all men in this study were Medicare recipients, our study highlights that area-level characteristics have an impact on the incidence of advanced prostate cancer above and beyond one’s access to insurance coverage,” Dr Jayasekera said.

Using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database (2000-2007) linked to US Census and County Business Patterns data,  Dr Jayasekera’s group analyzed PCa diagnoses among 37,760 Medicare beneficiaries aged 70 years or older (mean 76.5 years) diagnosed in 158 counties in SEER-covered regions.

The study showed that African American race, older age (80 years or older), higher Charlson comorbidity index (CCI), poor performance status proxies, no colon cancer screening, and receiving 0-1 influenza shots 5 years prior to PCa diagnosis were significantly associated with a higher likelihood of late-stage PCa diagnosis. The study also demonstrated that rural location and low HSS characteristics were associated with a higher risk of receiving an advanced PCa diagnosis.

“In contrast to previous studies, our findings highlight that even with insurance coverage, county-level characteristics could still contribute to significant variation in late-stage prostate cancer incidence in older men,” the authors wrote. “This study demonstrates how health care environments characterized by SES and HSS indicators interact with individual characteristics and preventive health behavior to determine subsequent health outcomes among Medicare insured older men.”

The investigators theorize that the protective effect of SES may be related to individual resources that support a healthy lifestyle, such as consuming a healthy diet, engaging in regular exercise, and other factors. “HSS may contribute to greater access to health care, the quality of care received, and the timeliness or thoroughness of workup and diagnosis,” the authors wrote.

“This is an extremely important area of research and our results provide a starting point for further research on the explanatory pathways between county-level characteristics and advanced prostate cancer,” Dr Jayasekera said. “The results of our study suggest several ways clinical practice or policy could help improve outcomes including the use of location-based screening policies, or the provision of more information regarding prostate cancer screening in areas with poor SES and HSS.”

She cautioned, however, that more research is warranted to better understand how resources and interventions could be tailored to different counties based on their SES and HSS characteristics.  The authors noted that the clinical burden of metastatic PCa is disproportionately higher among older men, with studies showing that approximately 89% of deaths due to PCa occur among men aged 65 years or older. The US Preventive Services Task Force recommends against annual PSA-based PCa screening among men aged 70 years and older.

Of the 37,760 men in the study, 2309 (6%) were diagnosed with distant PCa. In this group, 18.8% received annual PSA tests 4 or more times over a period of 5 years prior to diagnosis compared with 27.4% who received 2 or 3 annual tests and 53.8% who received 1 or no annual tests. The proportions were 44.8%, 30.9%, and 24.3%, respectively, for the study population as a whole and 46.5%, 31.1%, and 22.3%, respectively, for men with localized or regional PCa.

The new findings suggest that the benefits of PSA-based screening may vary in different counties. Lisly Joel Chery, MD, Assistant Professor of Urology at MD Anderson Cancer Center in Houston, said the new study does an excellent job of documenting the complex interaction of various factors that affect PCa diagnosis, such as patients’ biology, health care choices, and the setting in which patients make those choices.

“I do believe that PSA screening needs to be more nuanced; however, the more nuanced a recommendation is, the harder it is for all health care providers to remember and subsequently correctly follow that recommendation, Dr Chery said.

Related Articles

The American Urological Association does not recommend routine PSA screening for men aged 70 years or older, but it does recognize that some men in that age group are in excellent health and may benefit from screening. “Studies like this one give clinicians more information to help determine which patients greater than age 70 may benefit from screening,” Dr Chery said.

William T. Lowrance, MD, of the Huntsman Cancer Institute and Associate Professor of Urology at the University of Utah in Salt Lake City, said the new study’s findings that lower use of PSA testing, lower SES, lower health services supply, and black race were associated with higher rates of advanced PCa. Still, the findings underscore issues that can be easily overlooked. “They found significant geographic variation of advanced prostate cancer incidence, begging the question of whether or not screening policies focused on location-specific interventions might reduce the geographic disparities seen in these older men. Importantly, this paper does not just point out disparities in prostate cancer incidence in this large sample of Medicare-eligible men, but additionally offers potential interventions that with implementation may reduce the observed disparities in prostate cancer outcomes.”

Clinicians must balance the risk of overdetection and overtreatment when considering PSA screening in older men, Dr Lowrance said. He is not certain, however, that a blanket policy recommending no PSA screening for all men over 70 years is ideal. “Targeted PSA screening in older men with specific risk factors might be an effective way to reduce the disparities noted in this study,” Dr Lowrance said.

Cathy Handy Marshall, MD, MPH, Assistant Professor of Oncology at Johns Hopkins University School of Medicine in Baltimore, said the most recent data have shown an increase in the rate of distant PCa diagnosed. “Changes in PSA screening recommendations are thought to be contributing to this change,” Dr Marshall said. “This article [by Dr Jayaseker and colleagues] provides helpful information for patients and clinicians to consider because PSA screening should be based on a number of patient level factors, and there may be times when PSA screening after age 70 is reasonable and could significantly improve the health of the individual.”

Parth Modi, MD, MS, a clinical lecturer in urology at the University of Michigan in Ann Arbor, said the study by Dr Jayasekera’s group is important because until now few studies have attempted to quantify the impact of regional and market factors on PCa. An important next step would be to see if similar factors and the health care market and socioeconomic status of the county where a patient resides affects outcomes such as overall survival and quality of life. “That is what really matters,” Dr Modi said.

Reference

Jayasekera J, Onukwugha E, Cadham C, et al. Epidemiological determinants of advanced prostate cancer in elderly men in the United States. Clin Med Insights Oncol. 2019; 13:1179554919855116.

doi: 10.1177/1179554919855116