In a southwestern U.S. population having renal cell carcinoma (RCC), patient and disease characteristics differ by race/ethnicity in ways that may have implications for prevention, diagnosis, prognosis, and treatment, finds a single-center cohort study.
Investigators led by Ken Batai, PhD, of University of Arizona, Tucson, retrospectively reviewed the medical records of 294 patients with RCC as their first cancer who underwent partial or radical nephrectomy: 151 European Americans, 95 Hispanic Americans, 22 Native Americans, 9 African Americans, and 17 other race/ethnicity. About 12% overall had metastases at presentation.
On average, compared with European Americans, Hispanic Americans were about 5 years younger at diagnosis (55.8 vs. 60.5) and had higher odds of diagnosis before the age of 50 (odds ratio, 2.77), according to results published in Clinical Genitourinary Cancer.
Native Americans were even younger (49.7) and had dramatically elevated odds of diagnosis before that age (odds ratio, 6.23).
Relative to their European American counterparts, Hispanic Americans less commonly smoked (30.5% vs 48.6%) and African Americans more commonly had chronic kidney disease (37.5% vs. 5.8%). Both groups had higher prevalence of diabetes (45.6% and 54.5% vs. 21.7%). In addition, Native Americans had higher body mass index (35.2 vs. 30.7).
Clear cell histology was seen in 78.8% of European Americans, but in 92.6% of Hispanic Americans (odds ratio, 2.79) and 86.4% of Native Americans. African Americans more commonly had stage III or IV disease at diagnosis (77.8% vs. 35.3%; odds ratio, 6.51), but the racial/ethnic groups did not differ significantly on grade, tumor size, or presence of necrosis.
Among the Hispanic American patients undergoing radical nephrectomy, disease was more commonly of stage III or IV at diagnosis in those who were aged 65 or older (odds ratio, 10.48) and those who spoke Spanish as their primary language (odds ratios, 4.61).
The reasons for the observed racial/ethnic disparities remain unclear, according to Dr. Batai and his coinvestigators. Nonetheless, “it is necessary to better understand the clinical characteristics of these underserved Hispanic American and Native American populations with high kidney cancer burden,” they wrote.
“Our findings can direct future research toward elucidating the difference in tumor behavior among the different ethnic groups and health care issues causing poor outcomes,” they concluded. The findings also “bring ... awareness to practitioners treating patients from these racial/ethnic minority groups regarding the clinical characteristics and underlying issues in these patient populations.”
The study was supported by the American Cancer Society and the Partnership for Native American Cancer Prevention.
SOURCE: Batai K et al. Clin Genitourin Cancer. 2018 Oct 26. doi: 10.1016/j.clgc.2018.10.012.