CDC may join cancer cluster analysis
Initial study shows further investigation needed in Poolesville
This story was corrected on Feb. 6
Initial analysis on whether there are an unusual number of cancer cases in Poolesville has "raised questions," and the U.S. Centers for Disease Control and Prevention is expected to help investigate further, according to a county health official.
The Montgomery County Department of Health and Human Services initiated a cancer cluster study in December after being contacted by a concerned resident. The first stages of the investigation, which analyzed Poolesville's Standardized Incidence Ratio, a comparison of expected cancer cases in a population to observed cancer cases, did not reveal unusual patterns, county health officer Dr. Ulder Tillman said during a presentation at Monday night's town commissioners meeting. However, the county received additional calls from Poolesville residents that warranted further study, she said.
"These have raised questions for us that we don't have complete data or information for," said Dr. Clifford Mitchell, director of environmental health coordination at the Maryland Department of Health and Mental Hygiene, which provided assistance to the county in its analysis. "…It really does suggest that further evaluation is warranted."
Tillman said that "some things may or may not be unusual" but would not elaborate, citing privacy concerns. After the meeting, she said questions had been raised about the number of cancer cases and the specific kinds of cancers reported.
Mary Anderson, a county spokeswoman, would not say how many people contacted the health department about cancers in Poolesville, also citing privacy concerns. She said she was not aware of any other times that the CDC participated in a cancer cluster study in Montgomery County.
More than 100 people attended the meeting at Poolesville's Town Hall, and residents lined the walls and spilled out into the foyer.
"I think we got their attention and got them looking at it," said resident Catherine Poss, who was diagnosed with a rare salivary gland cancer two years ago. "…We'll get an answer one way or another, and you can't ask for anything more than that."
Western upcounty residents have long discussed whether cancer rates in their communities are unusually high and wondered if environmental factors are to blame.
Resident Fred Kelly, whose wife was recently diagnosed with renal cancer, contacted the county in December after becoming concerned about high levels of naturally occurring alpha radiation-emitting particles in the town's water supply, particularly radon. The town's water has never been out of compliance with federal and state standards.
There have been initial discussions with CDC officials about the agency participating with the study, Mitchell said. The county and state plan to formally ask for assistance and expect that the CDC will agree, he said.
"Looking at the questions that have been raised, we thought it was prudent to ask for outside assistance," Mitchell said. After the meeting, Tillman said she did not know how common it was for the CDC to participate in local cancer cluster studies.
A cancer cluster is a "greater than expected number of cases of similar cancers occurring in a short period of time among people who live or work near each other," according to documents provided by the county health department. The county will now look at whether there is an increased risk of cancer within the cluster and whether there is a common exposure. Only two out of every 1,000 suspected cancer cluster studies reach this stage, according to the documents.
Investigators are also waiting on Maryland Cancer Registry data from 2004-06, which is expected to be finalized soon, Mitchell said. The study could take several weeks to several months to complete, he said.
The boundaries of the study area still need to be determined, Mitchell said.
To report a cancer case in Poolesville or find out if a specific case is in the state registry, contact the county health department at 240-777-1245.