Epidemiology and Psychiatric Correlates of Cancer among Homeless and Unstably Housed Veterans in the VA Health Care System

Abstract Background: This study examined the incidence and correlates of cancer among homeless and unstably housed (HUH) veterans as compared with stably housed (SH) veterans. Methods: Using Veterans Affairs (VA) administrative data from 564,563 HUH and 5,213,820 SH veterans in 2013 and 2014, we examined the types and stages of 69 different types of cancer diagnosed among HUH and SH veterans. Sociodemographic and psychiatric characteristics associated with cancer were also examined. Results: The 1-year incidence rate of cancer was 21.5% lower among HUH veterans than SH veterans (0.68% and 0.86%, respectively). There was no difference in the most common stages and types of cancer among HUH and SH veterans. The most common primary sites of cancer were in the prostate, lung, and bronchus. HUH veterans were more likely than SH veterans to have cancer of the liver and intrahepatic bile ducts (∆4.79%). Among HUH veterans, older age and alcohol use disorder were associated with greater risk for any incident cancer while suicidal ideation/behaviors were associated with lower risk. Psychiatric conditions were often diagnosed before cancer diagnosis for SH and HUH veterans; rates of substance use disorders and suicidal ideation/behaviors decreased in HUH veterans after cancer diagnosis. Conclusions: The VA health care system serves many HUH veterans with cancer. Mental health and substance use disorders are important to treat in veterans at risk of cancer and as potential sequalae of cancer. Impact: The high prevalence of psychiatric disorders in HUH populations is important to consider in the diagnosis and treatment of cancer in these populations.