Investigating the Impact of Geographic Location on Cancer Stage at Diagnosis: A National Study of the SEER Cancer Registry

Authors: Andrilla CH, Evans DV, Moore TE, Wong KM, Yung R

Category: Cancer Health Disparities
Conference Year: 2020

Abstract Body:
Purpose of the study: This study examined the extent to which United States’ rural residents present at a more advanced stages of colorectal cancer (CRC) and breast cancer compared to non-rural residents. This study also examined the patient factors associated with late stage at diagnosis for these cancers. Methods: Using the 2010-2014 Surveillance, Epidemiology and End Results Incidence data, 132,277 patients with CRC and 306,726 patients with breast cancer were stratified using their county of residence and the Department of Agriculture Urban Influence Codes into five categories (metro, adjacent micropolitan, nonadjacent micropolitan, small rural, and remote small rural). Logistic regression was used to investigate the relationship between late stage at diagnosis and patient characteristics and county-level characteristics including level of rurality, persistent poverty, low education and low employment. Results: In the adjusted analyses, the rate of stage 4 CRC at diagnosis differed across geographic classification with patients living in remote small rural counties having the highest rate of stage 4 disease (range: 19.2% in non-adjacent micropolitan counties to 22.7% in remote small rural counties). Patients in remote small rural counties also had higher rates of later stage breast cancer than their urban counterparts (15.5%, 13.2%, respectively). Uninsured patients and Medicaid insured patients were about twice as likely to be diagnosed at later stage breast cancer and 50% more likely to be diagnosed at stage 4 CRC than other insured patients. African American patients had higher odds of both later stage breast cancer (OR 1.27, 95% CI (1.22-1.32)) and stage 4 CRC (OR 1.19 95%, CI (1.14-1.24)) than white non-Hispanic women. Conclusions: Geographic residence is associated with the rate of late stage disease at diagnosis. Patient factors are associated with later stage breast and stage 4 CRC disease at diagnosis. Marginalized groups including African American and patients in poverty are disproportionality affected. Cancer outcomes are worse for rural patients, poor patients and African American patients and late stage at diagnosis may partially account for this disparity. These differences have persisted over time and suggest areas for further research.

Keywords: rural cancer disparities, cancer detection, cancer screening disparities