EPA may replace CDC as cancer cluster surveillance agency

The U.S. Environmental Protection Agency (EPA) would replace the Centers for Disease Control and Prevention (CDC) as the federal government’s lead agency for investigating suspected residential clusters of cancer, birth defects and chronic diseases, under the newly-proposed “Strengthening Protection For Children and Communities From Disease Clusters Act” under consideration in the U.S. Senate.

“The real strength (of the new bill) is it brings the EPA to the table when there’s concern about some health effect,” National Disease Clusters Alliance (NDCA) director Terry Nordbrock said.

That came as welcome news for some familiar with the CDC’s troubled investigations of two recent childhood leukemia clusters.

The CDC is a world-renowned center of expertise on infectious diseases. But cancer epidemiologists and toxicologists contacted by epiNewswire expressed skepticism that the CDC or the CDC’s Agency for Toxic Substances and Disease Registry (ATSDR) competently and aggressively investigate the environmental correlates of chronic disease clusters.

At recent congressional hearings, ATSDR Director Henry Falk was asked about the epidemiology of cancer clusters with suspected environmental causes. He described only the scientific limitations of such studies, according to news reports.

CDC failed to tell public of errors in Fallon leukemia cluster study

Much of the skepticism about the CDC’s commitment to cancer cluster investigations is rooted in the agency’s mishandling of an investigation into the Fallon, Nevada childhood leukemia cluster.

The Fallon cluster was the most profound elevation in childhood leukemia rates ever recorded. Between 1999 and 2005, at least 15 children in the small rural town of 8,500 were diagnosed with acute leukemias. Another boy was diagnosed in 1997. In addition, another six older children were diagnosed during the early years of the cluster with idiopathic thrombocytopenia, a local health care provider told epiNewswire.

The CDC and ATSDR investigated the Fallon cluster and a simultaneous childhood leukemia cluster in Sierra Vista, Arizona, between 2002 and 2007. An EPA scientist complained at the time that the CDC was “guarding its turf” in the Fallon cluster investigation, refusing to involve environmental epidemiologists or toxicologists from other agencies.

CDC contractor Battelle’s analysis of toxic chemical body burden (blood and urine concentration) data included systematic errors involving the use of incorrect denominators, a CDC official acknowledged to epiNewswire.

Battelle had been paid several million dollars by the U.S. Navy to help assess and clean up toxic waste at the Fallon Naval Air Station just south of town. CDC officials were unaware of that potential conflict of interest when they contracted Battelle to study the possible role of some of those toxic chemicals in Fallon’s leukemia cluster, an agency administrator told epiNewswire.

The CDC never publicly acknowledged the data analysis errors in the Fallon study or Battelle’s potential conflict of interest in that study. In fact, the CDC based some of its conclusions on the Battelle analysis, without disclosing in its final report on Fallon that there were doubts about the validity of that analysis.

The CDC’s discovery of the Fallon leukemia data analysis errors came just months after the agency’s public embarrassment over its own erroneous claims about adult obesity-related mortality rates, noted a former CDC employee familiar with the obesity study.

The CDC emphasized a correlation it identified with a particular gene, SUOX*628A, which was present in most of the leukemia case children in the Fallon and Sierra Vista clusters, but not healthy control children from each community.

But when statistical corrections were made for the large number of genes tested in the study, the SUOX finding was statistically non-significant, CDC officials acknowledged.

“This allele is about as common as blue eyes”, University of California San Francisco genetic epidemiologist and leading childhood leukemia researcher Joseph Wiemels said of the CDC’s finding. “It is certainly not the cause of the cluster.”

Senate Bill 3681 was introduced by Senate Environment  & Public Works committee chairwoman Barbara Boxer (D-CA), Sen. Amy Klobuchar (D-MN), Frank Lautenberg (D-NJ), and Bill Nelson (D-FL). The bill is known as “Trevor’s Law,” named for Trevor Schaefer, 20, a childhood brain cancer survivor.

The bill would authorize the EPA to investigate environmental pollution’s role in disease clusters, and was drafted in the wake of studies of a rare male breast cancer cluster among Marines once stationed at Camp LeJeune, North Carolina, a brain cancer cluster in Acreage, Florida, and a cluster of birth defects in Kettlemen City, Calif.

“Whenever there is an unusual increase in disease within in a community, those families deserve to know that the federal government’s top scientists and experts are accessible and available to help, especially when the health and safety of children are at risk,” said Sen. Boxer.

As epiNewswire reported in 2007, most state health departments lack the resources and staff expertise to investigate suspected chronic disease and birth defects clusters.

Bryant Furlow reported on the Fallon leukemia cluster and the CDC’s study for New Scientist magazine and The Lancet Oncology. Furlow is an award-winning investigative medical journalist.