乌鸦传媒

ORLANDO -- Flame retardant chemicals, commonly found in household furniture and electronics, may be associated with papillary thyroid cancer (PTC) occurrence and severity, researchers said here.

In a case-controlled study, there were higher levels of certain biomarkers, indicating exposure to the endocrine-disrupting chemical, polybrominated diphenyl ethers (PBDE), and possible links to the development of papillary thyroid cancer, according to lead author Julie Ann Sosa, MD, of Duke University in Durham, and colleagues.

In particular, exposure to decabromodiphenyl ether (BDE-209) and tris(2-chloroethyl) phosphate (TCEP) had the strongest associations with papillary thyroid cancer, as did TPHP household exposure, they reported at ENDO 2017.

Participants were 2.29 times as likely to have papillary thyroid cancer if their household dust concentrations of BDE-209 were considered high, defined as the greater half of dust concentration measured versus low concentrations (95% CI 1.03-5.08).

A co-authored by Sosa, reported an annual 3% rise in thyroid cancer incidence in the U.S. from 1974 through 2013.

"Thyroid cancer is the fastest increasing cancer in the U.S., with most of the increase in new cases being papillary thyroid cancer," Sosa stated in a press release. During a similar time, flame retardant chemical use and subsequent exposure has also steadily increased, leading her group to assess the association between the two variables.

The study included 70 participants with papillary thyroid cancer, matched with 70 healthy control participants. The researchers collected and analyzed dust samples following visits to the participant's homes, measuring for the flame-retardants, BDE-209, TCEP, TDCIPP, TCPP, and TPHP, to analyze for long-term exposure.

High exposure to particular flame-retardant chemicals, and subsequent associations with the severity of papillary thyroid cancer, also varied with the presence of the mutation, BRAF V600E. The authors reported that those with the highest levels of BDE-209 in the dust were 14.2 times as likely to have BRAF-negative (95% CI 1.63-123) and less aggressive tumors (small tumors without extra-thyroidal extension).

TCEP was more strongly associated with larger, more aggressive tumors, and participants with house dust TCEP levels above the median were 4.14 times likely to have papillary thyroid cancer with extra-thyroidal extension (95% CI 1.01-16.98). However, they were not significantly more likely to have papillary thyroid cancer without extra-thyroidal extension (OR 2.13, 95% CI 0.89-5.07).

Sosa told 乌鸦传媒 the strongest associations were with three very different flame-retardants. "One is a brominated flame retardant, the [BDE-209], and the other two are organophosphate flame retardants, so they're very different in that way. They're also very different in terms of where they're located in the home and in your life." For example, BDE-209 is commonly used in clothes and furniture, while organophosphate flame retardants are often found in hand wipes.

Future studies are needed to understand how mixtures of these particular flame-retardants could be modifying risk as a group, she said.

During an ENDO press conference, Lindsey Treviño, PhD, of Baylor College of Medicine in Houston, said she hopes "some of these results from these studies ... actually lead to better awareness for physicians and for patients ... these are things we need to start thinking about." She noted that that environmental exposures play a large role in many diseases, but this issue is often overlooked.

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