The role of metastatic burden in shaping mortality trends in patients with kidney cancer.

Abstract

e16536 Background: Kidney cancer, predominantly renal cell carcinoma (RCC), accounts for 2–3% of all adult cancers globally. The rising prevalence of risk factors such as obesity and hypertension has worsened the prognosis of metastatic renal cell carcinoma (mRCC). This analysis evaluates the United States (U.S) age-adjusted mortality trends from 1999 to 2020, aiming to address significant disparities in mRCC mortality across age, gender, race, urbanization, and geographic regions, with the goal of reducing its overall burden. Methods: A retrospective analysis of death certificate data from the CDC WONDER (Centers for Disease Control and Prevention Wide-Ranging Online Data for Epidemiological Research) database was conducted for metastatic renal cancer in adults aged 25 and older, spanning from 1999 to 2020, using the ICD-10 Codes C64 and C65 (malignant neoplasms of kidney) as the underlying cause of death and C77-C79 (metastatic neoplasm) as multiple causes of death. Age-adjusted mortality rates (AAMRs) per 1,000,000 individuals, annual percentage changes (APC) and average annual percentage change (AAPC), with 95% confidence intervals, were determined across sex, race/ethnicity, and geographical regions using Joinpoint analysis. Results: The study identified 45,006 metastasis-related deaths among adults with kidney cancer from 1999 to 2020, with an overall AAMR of 9.30 and an AAPC of 0.32. Initially, AAMRs declined until 2008 (APC: -3.92), followed by a gradual increase through 2020, peaking at 11.4 (APC: 3.63). Males, who accounted for 65.5% of total deaths, had an overall AAMR of 13.8—more than double that of females (5.8)—and consistently exhibited higher rates throughout the study period. Among racial and ethnic groups, Hispanics had the highest AAMR (12.1), while non-Hispanic (NH) Asians/Pacific Islanders had the lowest (5.0). Regionally, the Midwest reported the highest AAMR (10.1), whereas the Northeast had the lowest (7.2). Non-metropolitan areas also experienced elevated rates, with an AAMR of (11.4). At the state level, Arkansas had the highest AAMR (18.5), while the District of Columbia had the lowest (4.8). Conclusions: In conclusion, this study highlights notable disparities in metastatic kidney cancer mortality trends across demographic, geographic, and urbanization factors. While overall mortality initially declined, a resurgence in rates since 2008 underscores the need for targeted interventions. Elevated mortality among males, Hispanics, residents of the Midwest, non-metropolitan areas, and certain states like Arkansas emphasizes the importance of addressing these gaps to reduce the burden of metastatic renal cell carcinoma.