Black patients diagnosed with renal cell carcinoma had worse survival than white patients regardless of several patient and tumor characteristics including tumor stage and size, according to data from 39,350 patients in the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER) program.
“I suspect that many physicians may know already, perhaps even from their own clinical experience, that African American renal cell cancer patients have poorer prognosis,” said Wong-Ho Chow, PhD, of the University of Texas MD Anderson Cancer Center, Houston. “It may be less clear, however, that this racial disparity in survival exists even within subgroups of patients with relatively homogenous clinical characteristics, such as tumor stage and histological subtype.”
Chow and colleagues examined data on patients diagnosed with renal cell carcinoma from January 1992 to December 2007 from the SEER program. They identified 39,350 patients who met their inclusion criteria; 11.1% of patients were black, and 88.9% of patients were white. Using these data, the researchers calculated relative survival rates in blacks compared with whites. The results of their analysis were published online in Cancer.
White patients with renal cell carcinoma had a 5-year relative survival rate of 72.6% compared with 68% in black patients. Black patients experienced an improvement in survival rates from 1992-1996 to 2000-2007 (64.8% to 70.6%), but the survival still lagged behind that of white patients during the same periods (67.6% to 76.7%).
“Compared to Caucasians, African Americans were more likely to be diagnosed with papillary
histological subtype of renal cell cancer, a type that is generally associated with a better survival
rate,” Chow said.
Despite that, the survival advantage seen in white patients compared with black patients was seen in papillary renal cell carcinoma and clear cell renal cell carcinoma.
In addition, black patients were more likely to be diagnosed with localized renal cell carcinoma and with smaller tumors. However, neither of these factors conferred a better survival rate among blacks compared with whites.
The researchers also found that more black patients were diagnosed with renal cell carcinoma aged 50 years or younger compared with white patients (26.3% vs 18.4%).
Overall, the survival advantage of white patients over black patients was consistently seen in all subgroups of patients, regardless of sex, age, tumor stage or size, tumor subtype, or type of surgical treatment.
Currently, Chow said, they do not have enough data on what other factors might be contributing to this disparity.
“Our study lacks other data, for example on comorbid conditions, lifestyle changes, and genetic susceptibility, which would allow us to evaluate more comprehensively reasons for the apparent racial disparity in survival,” she said.