CHARLOTTE, NC (Bruce Henderson/The Charlotte Observer) - A year-long analysis of environmental clues to the unusual number of rare eye cancers in the Huntersville area has come up empty, even as attention turns to a similar rash of cases in Alabama.
Ocular melanoma is diagnosed in only about 2,500 adults a year, at a rate of about five new cases in 1 million people. Victims are most often men, and the odds of getting it increase with age.
But a number of the nearly two dozen cases linked to Huntersville have been young women. That's also true two states away, where 18 people who studied or worked at Alabama's Auburn University in the 1980s and 1990s have developed the disease.
The Huntersville town board spent about $15,000 of a $100,000 legislative grant for the analysis, which traced where each of 23 cancer patients had spent time before their diagnoses. The work hoped to detect patterns that would suggest possible links to cancer.
But the study "did not provide any clarity on specific associations which expand upon and is consistent with the earlier analysis by the state," John Cassels, principal scientist at Pennsylvania-based Geodesy Inc., told Huntersville commissioners Monday night. The state analysis, done in 2015, concluded there was not an unusual number of the cancer cases.
Northern Mecklenburg County has seen toxic releases to air and water, asbestos contamination and electromagnetic radiation from power lines. None could be linked to ocular melanoma, Cassels said.
A previous study of environmental contaminants at Hopewell High School, which had been viewed as a potential common link among some of the cases, found nothing. The Geodesy analysis of the movements of 23 patients with ties to northern Mecklenburg County instead found potential "hotspots" of the disease to be north of the Huntersville school.
Former Huntersville commissioner Rob Kidwell said the families of some cancer patients still want air, soil and water to be analyzed at those hotspots and compared to sites elsewhere. Cassels said such analysis isn't warranted, and other experts have said such tests aren't practical because of the large number of potential contaminants.
"Everybody's aware we're not going to find a smoking gun, but If we take samples and compare them to soil from elsewhere it puts minds to rest," Kidwell said. "It gives us a sense of, we know it's not the soil, not the water, then we can move on."
Money from the legislative grant remains unspent, officials say, and could be used for such tests.
"As far as I'm concerned, we're not done," said Dr. Michael Brennan, the retired ophthalmologist who's served as a volunteer coordinator of the Huntersville studies.
Genetic testing of some of the Huntersville patients has shown that the disease was not passed down through families. But researchers at Columbia University in New York are studying tumors from the Huntersville area in hopes of learning more about the progression of the disease, risk factors and how to treat it.
Brennan was among physicians who traveled earlier this year for a conference in Alabama, where the ocular melanoma cases at Auburn were discussed.