Mapping cancer

Posted July 31, 2009, at 7:47 p.m.

What is the relationship between Maine’s lung cancer cases and the location of the state’s craggy granite outcroppings? Why is the incidence of melanoma — a life-threatening cancer of the skin linked to prolonged exposure to sunlight — not highest along the lobster coast, as public health experts might predict, but rather in-land, in the forested foothills of Maine’s western mountains? Is there a connection between rates of breast and prostate cancers and the hormone-disrupting properties of arsenic found in natural deposits — as well as in industrial spills and dumps — around the state?

According to a 2005 report published by the U.S. Centers for Disease Control and Prevention, Maine had a rate of 510.3 cases of invasive cancer per 100,000 people — much higher than the national average of 459.9 cases per 100,000.

In a unique public health research project, one of Maine’s oldest mapping companies and its newest genetics institute are attempting to answer questions about how the natural environment, man made toxins and genetic factors are linked to the state’s highest-in-the-nation cancer rate.

“Is it just our demographics, or is there something else at work?” wonders Janet Hock, director of the Brewer-based Maine Institute for Human Genetics and Health. Factors such as age, income, education and lifestyle are clearly predictive of cancer and chronic illnesses, Hock said, but such human elements are only part of the story.

“In the 1970s, the thinking was that cancer is all environmental,” she said. “Then in the ’80s and ’90s we had the genetics revolution and we thought, ‘No, everything is genes.’ Now we know it’s a mix.”

Tapping into millions of dollars in public research funding, Hock is heading up a long-range, multilayered study of that mix, partnering with the venerable James W. Sewall Co. in Old Town, established in 1880.

In addition to identifying a broad range of environmental features in Maine, the project will map the locations of cancer cases and clusters. It will also have access to relevant data about the genetic factors of affected individuals drawn from a repository of frozen tissue specimens donated by cancer patients.

The tissue bank, still in its earliest stages, is maintained by the Maine Institute for Human Genetics and Health and housed at the institute’s laboratory on Sylvan Road in Bangor.

“It’s still really controversial how much the environment contributes to health,” Hock said. “That’s partly because most scientists study only one toxin at a time. But by mapping, we can study multiple toxins.”

The “BioGeoBank of Maine,” as the mapping project has been named, will collect clinical, laboratory and patient-survey data — stripped of identifying information — from the Maine Institute for Human Genetics and Health and its parent company, Eastern Maine Healthcare Systems. It will also compile detailed environmental, industrial, agricultural and geological data from a variety of public sources. Through a limited-access computer gateway, researchers will be able to explore correlation between disease and the environment at a given moment in time and over a span of years, adding and subtracting layers of information to refine and expand the as-sociations.

According to Jim Page, chief executive officer of the James W. Sewall Co., the project will map existing data from state and federal agencies, municipal offices and other sources. The information includes the locations of paper mills, tanneries and other industrial sites, pesticide application areas, watersheds, sites of toxic spills and dumps, natural deposits of arsenic and mercury, and more.

The information comes in many forms, and part of the challenge is translating it into a common digital language.

“We have to be able to aggregate this information, to put it all into a common format,” Page said.

The project, when it is up and running, will allow researchers to access information over time — reaching back, for example, to compare recorded levels of natural arsenic in a given area in 1990 to anticipated levels in 2010, and correlate those levels with breast cancer rates in the same area.

More complexly, researchers will be able to examine what happens to cancer rates when low levels of naturally occurring radon gas mix for years with applications of long-lived pesticides such as DDT and Agent Orange — then tie in genetic factors that could make that combination deadly to some Mainers and harmless to oth-ers.

One element that makes Maine ideal for such a project is its small, genetically homogenous population with a tendency to stay put over time. A 2000 county-by-county map from the U.S. Census Bureau shows that a high percentage of Mainers, especially in northern and rural areas, have lived in the same home for more than 30 years. That gives researchers an important opportunity to study a specific population of people over a period of decades.

“The medical community has long been making do with data assembled for other purposes,” Page said. “What’s unique about this project is the content of both clinical and GIS [Geographic Information Systems] and the level of detail for epidemiological purposes.”

Initially, the data will be available to researchers from the Maine Institute for Human Genetics and Health and its research partners at the University of Maine in Orono and The Jackson Laboratory in Bar Harbor. Over time, Hock said, she expects to expand access to other groups.

“My intention is to facilitate research,” she said.

Asked if the mapping project might implicate industrial facilities such as paper mills and chemical plants where cancer-causing or otherwise toxic materials may have been dumped, spilled or discharged into rivers, both Page and Hock demurred.

The mapping project is a public health project, they said, and is not intended to point fingers at industry.

“We’re dealing with public information — data from DEP and EPA,” Page said, referring to the Maine Department of Environmental Protection and the U.S. Environmental Protection Agency. “There are no secrets being revealed.”

A beginning baseline of geographic information for Aroostook, Penobscot, Washington and Hancock counties could be ready by the end of this year, according to Page. Hock said a meaningful number of tissue samples would be available in about 12 months.

But the project is still in its early phases. As more data are compiled and entered into the system, researchers will be able to expand their queries to include other disorders with suspected links to both the environment and genetic traits, such as allergies, lung disease and neurological problems.

mhaskell@bangordailynews.net

990-8291

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