Geographic Disparity of Outcome in Patients With Cancer Over Decades: The Surveillance, Epidemiology, and End Results

Abstract

Background: Improvements in prevention, early detection, and effective cancer therapy have decreased cancer-related mortality; however, significant health disparities exist. Therefore, we investigated the impact of these disparities on survival.

Methods: In the Surveillance, Epidemiology, and End Results, we identified 784,341 patients with cancer between 1990 and 2016 in Georgia, 68,493 between 1990 and 1999; 371,353 between 2000 and 2009; and 322,932 between 2010 and 2016. We assessed the overall survival (OS) of patients with all cancers, chronic myeloid leukemia (CML), and lung cancer, given the dramatic improvement in outcomes in patients with CML since 2000 compared to the generally considerably worse outcomes in lung cancer. In addition, we assessed the distance from each county to the Georgia Cancer Center (GCC) or the National Cancer Institute-designated Cancer Center (NCI-CC).

Results: The 5-year OS of patients with any cancer was 55%, and the 5-year OS of each county ranged from 33% to 82% (interquartile range, 51%-65%) (P < .001). In patients with lung cancer and CML, the 5-year OS rates were 15% and 52%, respectively. The geographic differences between counties were relatively small and constant over time for patients with lung cancer. However, geographic differences were more prominent in patients with CML and widened after the introduction of modern therapies. Multivariate Cox regression showed that age, median county income, race, and distance to GCC or NCI-CC were predictive factors.

Conclusions: Significant disparities in cancer care exist among geographic locations. Geographic differences in survival appear more prominent when highly effective therapies are available.

Keywords: All cancers; Chronic myeloid leukemia; Health care distrubution; Lung cancer; Survival.