© 2005-2012 American Society of Clinical Oncology (ASCO). All rights reserved worldwide.
Posted online November 22, 2010 on www.jco.org
An analysis of more than 3,500 children with neuroblastoma showed for the first time that blacks and Native Americans were more likely to have high-risk, aggressive disease than whites. Both groups also had worse survival - both overall and living disease-free without recurrence. In addition, neuroblastoma recurred at a higher rate in blacks compared to whites among highrisk patients who remained disease-free for two or more years after diagnosis.
In contrast, the prevalence of high-risk neuroblastoma among Asian and Hispanic populations was not much different from whites. According to the researchers, this black-white difference in high-risk neuroblastoma suggests that blacks may have a genetic predisposition that contributes to developing high-risk disease.
Neuroblastoma, a disease of specialized nerve cells, is the most common extracranial solid cancer in childhood and the most common cancer in infancy, with an annual incidence of about 650 new cases in the United States. The disease can be varied, and is categorized into high-, intermediate- and low-risk groups based on disease characteristics and biology.
Susan Cohn, MD, and her colleagues analyzed data collected on 3,539 patients with neuroblastoma enrolled in the Children's Oncology Group ANBL00B1 biology study, which was conducted between 2001 and 2009 and aimed at collecting information on patients and their tissue samples to determine prognosis and appropriate therapy.
They found that blacks and Native Americans were more likely to have high-risk disease (57 percent and 68 percent, respectively) than whites (43 percent). Only 43 percent of Hispanic children also were high-risk. The five-year eventfree survival for white children was 67 percent, 69 percent for Hispanics, 62 percent for Asians and 56 percent for blacks. Native Americans had the lowest: 37 percent. Both white and Hispanic children had the highest five-year overall survival (75 percent), whereas black and Asian children had 67 percent and 63 percent, respectively. Native Americans again had the lowest survival: 39 percent.
The higher recurrence rate found in black children two years after initially responding to their treatment suggests that blacks are more likely than whites to be resistant to chemotherapy, and that there was disease left behind from their initial treatment that led to relapse.
Cohn's group and other researchers are planning studies focused on better understanding the genetic underpinnings behind some of these observed racial differences.
What this Means for Patients
For children with neuroblastoma, treatment is typically based on disease characteristics and biology, and patients tend to be divided into high-, intermediate- and low-risk. In this study, researchers found that race and ethnicity may also help provide insights into the type of neuroblastoma a child has. They showed that blacks and Native Americans have a higher proportion of high-risk, aggressive disease and as a result, tend to do more poorly than white children. A better understanding of the underlying biological explanations behind such racial and ethnic differences may help researchers identify patient risk, and develop more effective, individualized therapies.