Cancer Survival Differences Between Rural and Urban Populations During the Opioid Epidemic: A SEER Analysis

Multiple measures of health and wellness have worsened for rural communities in the last two decades. Few studies have sought to characterize the rural-urban difference in 5-year cancer survival data in a nationwide sample over that time.

We analyzed cause-specific five-year survival data for prostate, breast, colorectal, pancreatic, lung, and liver cancers diagnosed from 2000-2016 among rural and non-rural populations using the Surveillance, Epidemiology, and End Results Database. We explored the CDC Wonder Database for drug related mortality in rural and non-rural populations. Ordinary least squares regression assessed temporal survival trends, and analysis of covariance compared the statistical significance in annual change in survival between groups.

We created a cohort of 2.96 million individuals, of whom 93% were from urban areas and 7% were from rural areas, and observed significant differences in demographics between groups within each cancer type. Five-year survival improved over time for all cancers except prostate; however, gains were consistently inferior for rural populations. Rural-urban differences in survival were present at year 2000 and widened by 2016 for breast (1.8% to 2.9%), colorectal (2.1% to 3.0%), pancreatic (0.2% to 4.2%), lung (2.5% to 8.7%) and liver cancer (2.1% to 14.0%) and there were significant differences in the rate of change in cancer mortality in all cancers (p<0.05) except for prostate cancer (p=0.57). We also found significant worsening (p<0.0001) of drug related mortality disparities between rural and urban populations from the years 1999 to 2015.

From 2000 to 2016, rural-urban disparities in cancer survival widened for five of six major cancers during the same period in which national drug overdose rates increased in rural populations.