Kidney cancer incidence and mortality among American Indians and Alaska Natives in the United States, 1990-2009

Objective. kidney cancer incidence has continued to increase in the United States for all racial/ethnic groups. American Indians and Alaska Natives (AI/ANs), both men and women, are at greater risk of developing and dying of kidney cancers than other racial/ethnic groups. The objective of this study was to describe rates and trends in kidney cancer incidence and mortality and identify disparities between non-Hispanic AI/ANs and non-Hispanic white (NHW) populations.

Methods. To minimize the misclassification of race, Indian Health Service (IHS) patient registration database was linked to cancer registry records and National Death Index (NDI). We calculated age-adjusted kidney cancer incidence (2001-2009) and death rates (1990-2009), rate ratios, annual percent change (APC), and corresponding 95% confidence intervals (CIs)  by sex, age, and Indian Health Service (IHS) region in the Contract Health Service Delivery Area (CHSDA) Counties.  

Results. There were 2,088 AI/AN kidney cancer cases diagnosed from 2001-2009 and 1,215 non-Hispanic AI/AN kidney cancer deaths from 1990-2009 in the CHSDA counties. Non-Hispanic AI/ANs have a 1.6-fold higher kidney cancer incidence and a 1.9-fold higher kidney cancer death rate than NHWs. Despite a significant decline over the past twenty years in kidney cancer death rates for NHW (APC=-0.3; 95% CI=-0.5, 0.0), death rates for non-Hispanic AI/ANs remained stable (APC=0.4; 95% CI=-0.7, 1.5). Incidence rates of kidney cancer continue to rise, but more rapidly for non-Hispanic AI/ANs (APC=3.5; 95% CI=1.2, 5.8) than NHWs (APC=2.1; 95% CI=1.4, 2.8).

Conclusions. Non-Hispanic AI/ANs have greater risk of developing and dying of kidney cancers. Incidence rates have increased faster in non-Hispanic AIAN compared to NHW.  Death rates have decreased significantly in NHW, but remained stable in non-Hispanic AI/AN. Racial disparities in kidney cancer are widening.