Blacks and Hispanics have fewer cases of acute leukemia compared to whites but they die at a substantially higher rate, according to study results presented at the Fourth AACR Conference on The Science of Cancer Health Disparities, held here Sept. 18-21, 2011.
From 1998 to 2008, blacks had a 17 percent increased risk of dying from acute leukemia and Hispanics had a 12 percent increased risk compared to white patients.
When separated into the two forms of acute leukemia - acute lymphoblastic leukemia (ALL) and acute myelogenous leukemia (AML) - the difference in mortality was even more striking. Blacks and Hispanics diagnosed with ALL had a 45 percent and 46 percent greater risk, respectively, of dying than whites; whereas increased risk of death from AML was 12 percent higher in blacks and 6 percent higher in Hispanics compared to whites.
"These data tell us that the disparity in overall survival in acute leukemia is driven by higher death rates in ALL," said the study''s lead researcher Manali I. Patel, M.D., M.P.H., postdoctoral fellow in hematology/oncology at the Stanford Cancer Institute in Stanford, Calif.
"We don''t know the reason for the disparity, but now that we know it exists we can investigate why it occurs," she said. "Like all disparities in cancer there could be any combination of influences; however, we believe that socioeconomic factors and access to care may be playing an important role."
Patel and colleagues used the National Cancer Institute''s SEER database, which reports cancer incidence, prevalence and survival from multiple sites and represents 28 percent of the U.S. population. They examined statistics from 40,951 patients with acute leukemia during the 10-year time period. This included 2,299 black, 4,428 Hispanic and 22,035 white patients, of which 1,953 blacks, 3,322 Hispanics and 18,980 whites died within five years of diagnosis. The researchers discovered that minority patients who develop adult leukemia die from it more often than white patients.
"This paradox is seen in other solid tumors, such as breast cancer. It occurs less frequently in black women, but mortality rates, stage for stage, are higher," Patel said. "Now that we have taken the crucial first step to document this disparity in acute leukemia, we need to understand the factors behind it so we can address and correct it."