Disparities in prostate cancer survival in Appalachian Kentucky: a population-based study

INTRODUCTION: Prostate cancer (PC) is the most common male cancer in the USA. When comparing the incidence and mortality rates of PC, the Surveillance Epidemiology and End Results data of 2005-2014 show that Appalachian Kentucky had a lower incidence (113/100 000 v 137/100 000) but a higher mortality rate (23.8% v 21.8%) when compared to non-Appalachian Kentucky. The aim of this study was to further characterize the survival disparities of PC between Appalachian and non-Appalachian Kentucky. METHODS: All stages of PC patients diagnosed between 2007 and 2011 were collected through the Kentucky Cancer Registry. Baseline characteristics and survival outcomes were compared between Appalachian Kentucky and non-Appalachian Kentucky, using Pearson χ2 and Cox regression analyses in this population-based analysis. RESULTS: Of 12 871 patients studied, 3482 (26.8%) were from Appalachian Kentucky whereas 8489 (73.2%) were from non-Appalachian Kentucky. Caucasians predominated in both groups. Most Appalachian Kentucky patients were aged 65-74 years. Appalachian Kentucky patients had a higher Gleason score, higher prostate specific antigen (PSA), more aggressive histologic grade, more distant disease, higher comorbidity score, lower education, and higher poverty compared to patients from non-Appalachian Kentucky. There was a 5-year survival difference between Appalachian Kentucky and non-Appalachian Kentucky in unadjusted analysis (p<0.001) that disappeared after adjusting with Cox regression analysis (p=0.4). However, worsened survival was still seen with higher Gleason score, higher PSA, distant stage disease, higher Charlson comorbidity index, and very low high school education (p<0.001). CONCLUSION: In this population-based analysis, this study shows a significant difference in PC survival between Appalachian and non-Appalachian Kentucky. The difference was not related to geographic location, but rather to high comorbidity score, high poverty rate, and low education. Additional research is needed to understand the healthcare restraints for Appalachian Kentucky.