Geographic disparity of outcome in patients with cancer over decades: The surveillance, epidemiology, and end results.

Abstract

1574 Background: Improvements in prevention, early detection and therapy of cancer have decreased cancer related mortality yet health disparities continue to exist. We investigated the impact of such disparities in cancer survival. Methods: In the Surveillance, Epidemiology, and End Results, we identified 784,341 patients with cancer from 1990 to 2016 in Georgia; 68,493 in 1990-1999, 371,353 in 2000-2009, and 322,932 in 2010-2016. We assessed overall survival (OS) of patients with all cancers, chronic myeloid leukemia (CML), and lung cancer given the dramatic improvement in patient outcomes in CML since 2000 compared to the consistently poor outcome in lung cancer. We assessed distance from each county to the one National Cancer Institute-designated cancer center (NCI-CC) in Georgia. Results: The 5-year OS of patients with any cancer was 55% with median OS 80 months; the 5-y OS of each county ranged from 33% to 82% (interquartile range[IQR], 51%-65%)(P < 0.001). The improvement of OS was minimal over decades: 5-year OS was 52%, 55%, and 55% in 1990-1999, 2000-2009, and 2010-2016, respectively; the median was 69 months, 80 months, not reached, respectively (P < 0.001). In patients with lung cancer and CML, the 5-year OS was 15% and 52% with the median of 9 months and 67 months, respectively. The geographic difference between counties was relatively small and constant over time in patients with lung cancer, represented by the width in the range and IQR: range 5%-17%, IQR 9%-13%, median 13% in 1990-1999; range 2%-24%, IQR 10%-14%, median 14% in 2000-2009; and range 4%-24%, IQR 12%-17%, median 17% in 2010-2016. However, the geographic difference was more prominent in patients with CML and widened after introduction of modern therapy: range 20%-42%, IQR 26%-34%, median 32% in 1990-1999; range 14%-83%, IQR 38%-64%, median 53% in 2000-2009; and range 14%-80%, IQR 40%-57%, median 57% in 2010-2016. Multivariate Cox regression showed age (hazard ratio[HR],1.040;95% confidence interval[CI],1.039-1.040;P < 0.001), median county income (HR,0.919;95% CI,0.916-0.921;P < 0.001), African American (HR,1.021;95% CI,1.210-1.227;P < 0.001), and distance to NCI-CC (each 100 kilometers) (HR,1.021;95% CI,1.017-1.025;P < 0.001) as predictive factors. Conclusions: The disparity of cancer care exists between geographic locations. The geographic difference of survival seems more prominent when highly effective therapies are available.