A Texas Department of State Health Services analysis has found that the occurrence of leukemia, non-Hodgkin’s lymphoma and childhood brain cancers in two ZIP codes in Flower Mound, Texas, is within the expected ranges for males and females.
In response to community concerns about a possible cluster of cancer cases, DSHS analyzed the occurrence of childhood and overall leukemia, non-Hodgkin’s lymphoma, childhood brain cancer and female breast cancer in the 75022 and 75028 ZIP codes, using Texas Cancer Registry data from 1998 to 2007. The number of cancer cases occurring in these two ZIP codes was compared with the number of cases expected based on statewide rates.
“The incidence of all but breast cancer was within a statistically normal range in these two Flower Mound areas,” said Eric Miller, the DSHS epidemiologist who conducted the analysis. “We found nothing in the data to indicate the community is at higher risk for these types of cancers. However, we understand residents’ concerns and will continue to analyze new cancer data from these two areas.”
In ZIP code 75028 and both ZIP codes combined, the analysis did find a statistically higher than expected number of breast cancer cases, although there isn’t any established scientific link between breast cancer and benzene, the contaminant of chief concern to the Flower Mound community. The breast cancer result could be due to overall population increases in Flower Mound and the likelihood that women in this area are more frequently screened for breast cancer.
In response to requests for an assessment of more current data, DSHS also compared the average annual number of cases for the same four cancers in the same two ZIP codes from 2007 to 2009 with the average annual number of cases from 1998 to 2007.
The average annual number of childhood leukemia and brain cancer cases remained essentially unchanged from 2007 to 2009 compared with the previous 10 years. The average annual number of cases of overall leukemia, non-Hodgkin’s lymphoma and breast cancer was somewhat higher from 2007 to 2009.
However, DSHS cautions against drawing any conclusions regarding the 2007 to 2009 results, as the data for this time period are still being received and evaluated by the department. The number of individual cancer cases can fluctuate significantly from year to year, particularly with rarer cancers and in such small geographic areas. An annual increase or decrease doesn’t necessarily indicate a longer-term trend.
“Flower Mound’s significant population increase alone could account for a higher average number of cancer cases between 2007 and 2009,” Miller said. “We consider these figures a snapshot, not a complete picture, and that’s why we’ll continue to collect and analyze the data from this area.”
The full DSHS report on Flower Mound is available at: www.dshs.state.tx.us/epitox/consults/flower_mound32010.pdf.