2007.12.08 – Study finding link to rare cancer based on error
Study finding link to rare cancer based on error, officials say
Report cites Tamaqua cluster as indication of environmental cause.
By Chris Parker
Of The Morning Call
December 8, 2007
Federal and state health officials on Friday discredited a medical study, to be presented for the first time Monday, that suggests an environmental cause is a factor in Tamaqua and other areas in Schuylkill and Luzerne counties having more cases of a rare blood cancer than normal.
The research, to be presented at a medical meeting in Atlanta, didn’t determine a cause for the illnesses, but seems to contradict a statement by federal officials in October that environmental factors played no role in the unusually large number of cases of polycythemia vera.
On Friday, those officials said the study, which included contributions from a geneticist, the U.S. Agency for Toxic Substances and Disease Registry and others, was based on wrong information from the agency.
”We essentially jumped the gun in releasing something we ultimately don’t think is true,” said agency epidemiologist Steve Dearwent. The research is a ”stew” of expertise, he said, and ”the ingredient we added was not good.”
Here’s what happened, according to Dearwent:
The agency was conducting a study of the incidence of polycythemia vera, a rare blood disease that causes blood to thicken, causing heart attacks and strokes, in the Schuylkill/Luzerne county region. Polycythemia vera has been classified as a cancer. Its cause is unknown.
By late spring or early summer, data on 38 subjects began to roll in. Researchers looked at the data from many perspectives, including where each person lived over the span of 25 years.
Most people live in at least a few places over 25 years, but the researchers ”incorrectly assigned a single residential location for each of the subjects in the study,” Dearwent said.
The locations assigned showed only the proximity to other people in the study — meaning it might have artificially created a cluster, he said.
”You’re creating a cluster by the bias in that process,” he said. ”If you are assigning a historical location based on proximity to other cases, you’re creating a cluster that’s possibly not there.
Dearwent said the agency is ”still evaluating data on where people lived to better identify the locations of the cases.”
But the research to be presented in Atlanta used that geographic relationship as the basis of its findings — with scientists saying the geographical association of an unusually high number of cases is reason enough to say there’s some kind of external, environmental factor at work.
They noted particularly high rates around the McAdoo Associates Superfund Site, where a hazardous waste recycling business operated from 1975 to 1979, without checking where else people had lived.
People who had lived within 13 miles of the site developed the blood cancer at a rate 4.5 times as high as people in other parts of the counties and in neighboring Carbon County, the researchers found.
The abstract is to be presented by Dr. Ronald Hoffman of Mount Sinai School of Medicine in New York at a conference Monday at the Centers for Disease Control and Prevention in Atlanta.
Dearwent said Hoffman, a molecular geneticist, is not at fault for the error.
”Hoffman did only the genetic testing,” he said. He said the agency ”contributed field work” — the case information and analyses.
But Hoffman believes there could be a link between the disease and the environment.
”Based upon the data, there’s significant concern that there is something in the environment leading to the development of polycythemia vera in that area. The nature of what’s causing it is unknown at the moment and is going to require further study,” he told The Associated Press Friday.
The state Health Department, which also was involved in the agency study, supported the federal agency’s position.
Hoffman ”used what information was available to him at the time,” said Dr. Steve Ostroff of the department’s Bureau of Epidemiology. He said additional analysis ”calls into question some of those original findings.”
Both Dearwent and Ostroff said the information released at the October public meeting was accurate.
Tamaqua area environmentalist Dante Picciano was outraged at what he believed was a contradiction between what federal officials said in October and the new study’s suggestion of an environmental link.
”They are backpedaling,” he said. ”When you tell a lie, you’re going to have to tell another lie to cover that first lie.”
Just one case of polycythemia vera occurs each year in every 100,000 Americans, but it was occurring at a rate four times as high in Luzerne and Schuylkill counties, according to earlier estimates.
Local activists raised suspicions about a former toxic waste dump, the practice of filling abandoned coal mines with the ash created by coal-burning power plants and five power plants in Schuylkill County fueled by waste coal.
Specifically, residents were concerned about possible contamination of groundwater by industrial chemicals leaching from the McAdoo Associates Superfund site.