Putting NH’s cancer cluster in context

Reports of increases in pediatric cancer are not uncommon, and the causes are difficult to pinpoint

Ever since word spread in February of a pediatric cancer cluster in the Seacoast, parents have been reacting with a flurry of powerful emotions: fear that their own children could become sick, anger that they were not notified of the issue sooner, and perhaps a fraction of relief that their concerns were being taken seriously.

As experts continue to investigate the breadth of the problem and the potential cause of the cluster, it’s important to put the issue in context from a medical and scientific perspective.

The local cancer cluster involves fewer than five known cases of children with rhabdomyosarcoma, or RMS, in the five-town area of Rye, New Castle, Portsmouth, Greenland, and North Hampton. That is a higher-than-usual number, and the issue is therefore worthy of thorough investigation. But reports of cancer clusters across the nation are not uncommon, and it is not always possible to pinpoint an exact environmental cause.

The report
In March of 2014, a group of residents reported concerns over the number of local children with RMS to the N.H. Department of Health and Human Services (DHHS). As with all reports of this nature, the DHHS began an investigation.

“The initial report was just a high-level look at the number of cases initially reported,” said Dr. Benjamin Chan, New Hampshire’s state epidemiologist. “There was such a small number that we had to broaden our scope to a larger geographic area and look further back in time, and look at patients that had moved away.”

The DHHS searched the cancer registry and reached out to other states to determine how many cases of pediatric RMS were reported in the area between 2005 and 2014. They had to wait a full calendar year before the records were complete and they could publish their report on Feb. 2, 2016.

The results showed that there was a small excess of RMS cases involving fewer than five patients in the five-town area. The location of these patients does not offer an obvious pattern.

Until the report came out, many parents had been unaware that there was an investigation and were angry about the news. Dr. Chan admits the state could have done a better job of letting parents know, but their investigation is ongoing, and more information will be made public as it becomes available, he said.

Context and causes
Investigations into potential cancer clusters are more common than you might think. Reports of suspected clusters across the nation number in the thousands since 1990. Out of these reports, only about 70 cases have shown a higher number of cancer cases in one geographic area where migration, demographics, and genetics can’t account for the increase.

Each one of these clusters is studied in depth by the state’s department of health and human services. Out of those 70, only three were linked with a variable degree of certainty to an environmental cause, and only one of those cases had a clear cause.

Historically, the most informative investigations have resulted from cases that were linked by a common occupation. The cause of geographically linked clusters often remains unknown, with a long list of potential sources.

At this very moment, similar investigations of reported pediatric RMS clusters are being conducted in Georgia and New York.

In the Seacoast, the Coakley Landfill Superfund Site is a location of concern for many residents. Looking at a map of the five-town area, it’s easy to see why: The site borders Rye, Greenland, North Hampton, and Portsmouth.

The 92-acre landfill accepted industrial and other waste products from 1972 to 1985. In the 1990s, it was listed as a Superfund site, an Environmental Protection Agency (EPA) designation for a polluted location that requires long-term monitoring and cleanup. At that time, the community surrounding Coakley was surveyed to determine if there was an increase in cancer risk that may have resulted from the contamination. No increase was found.

The site is monitored every five years for contaminants known to cause disease. The EPA expands this list routinely as more research about the effects of chemical waste come to light.

After the news of the local cancer cluster broke in February, members of the EPA, N.H. Department of Environmental Services, Coakley Landfill Group, and the DHHS held a public meeting and gave an in-depth presentation on how the testing is done and the history of the site. At the meeting, residents also raised concerns about water contamination at Pease International Tradeport and potential radiation from the nuclear power plant in Seabrook.

The list of contaminants that raise concerns has grown over the last few months, making it difficult to pinpoint an answer, especially with fewer than five RMS cases. Such a small number of cases increases the margin of error, making the discovery of a single environmental cause unlikely.

Ongoing investigation
According to the Centers for Disease Control and Prevention, Rockingham County has a higher number of pediatric cancer cases than the rest of the nation.

The state DHHS plans to broaden the scope of its cancer-cluster investigation to a larger geographic area and look further back in time. Since their report was released in February, more parents and health professionals have come forward to report pediatric cancer cases, Dr. Chan said, though he did not specify where the reports have come from.

“We have started a working group to coordinate the effort,” Chan said. “The perspective that parents and health professionals bring to the investigation really helps.”

The process begins with a questionnaire that may include information on occupation, residence, source of drinking water, exposure to X-rays, and daily habits such as smoking and drug use.

Very little is known about RMS. It has been theorized that the mutations that drive the disease may occur prior to birth. Factors such as a lack of prenatal care or if the child’s father was over the age of 35 before conception have been shown to increase the risk of pediatric RMS. The research, itself, is in its infancy.

As of yet, no environmental cause of pediatric RMS has been named. That doesn’t mean one doesn’t exist, which is why potential exposures and daily habits will be explored as part of the ongoing investigation.

Children are more susceptible to environmental toxins and radiation than adults, making a rise in pediatric cancers in any area a great concern for the health of a community.

The list of environmental factors is substantial and growing each year as more research is done. President Obama’s Cancer Panel wrote an exhaustive report in 2009 listing potential environmental causes of cancer that include industrial, manufacturing, agricultural, lifestyle, medical, military, and natural sources.

In New Hampshire, the DHHS has been working to make information on the latest cancer research and treatment options available to the public. They recently released on online data information system called NH Health Wisdom, allowing users to search for state cancer rates and see the latest initiatives to improve overall health.

Education on exposure risk, prevention, and early detection are the strongest tools we have in the war on cancer. To learn more visit wisdom.dhhs.nh.gov/wisdom.

Jasmin Hunter is a photographer and medical writer who specializes in educational content for patients and researchers in the medical and biotech fields.

 About the table below: