Presence of paraben in breast tissue not linked to use of underarm products
Barr L. J Appl Toxicol. 2012;doi:10.1002/jat.1786.
British researchers examining the potential correlation between parabens and breast cancer discovered traces of the commonly used chemicals in tissue samples taken from all women involved in their study.
The researchers said their findings suggest that previously proposed links between breast cancer and the use of underarm cosmetic products may be unfounded.
Parabens - which are used as preservatives in pharmaceuticals, food and cosmetics - can act similarly to estrogen, which can fuel certain types of breast cancer.
Several prior studies have triggered concerns about their potential role in breast cancer, particularly stemming from the use of underarm products, because many breast cancers develop in the upper outer quadrant of the breast closest to the armpit.
The current study, however, showed traces of parabens were found in women who said they never used underarm cosmetics. Those findings raise more questions about how women are exposed to the chemicals, the researchers said.
"The finding of similar concentrations of parabens in the breast tissue of women who reported to be current, past or nonusers of underarm cosmetics suggests the parabens to have originated from a source other than underarm cosmetic application," Lester Barr, ChM, FRCS, a consultant surgeon at the University Hospital of South Manchester, England, and colleagues wrote.
The researchers studied tissue samples of 40 women with primary breast cancer who underwent mastectomies from 2005 to 2008.
They evaluated four tissue samples from each woman for traces of five types of parabens. The samples were taken from serial locations from the sternum to the axilla.
Researchers detected traces of at least one type of paraben in 158 of the 160 samples (99%). They found traces of all five types in 96 of the 160 samples (60%).
"Since paraben esters were measured in 99% of the samples, this demonstrates that, within the population studied, paraben was widely distributed both within and between breasts," the researchers wrote.
Researchers identified no correlation between paraben concentrations and patient age, breast-feeding history or tumor location.
The median value of parabens found in the breast tissue was 85.5 ng/g, about four times higher than median levels recorded in a 2004 study in Scotland that involved 20 breast cancer tissue samples.
Thirty-five of the 40 patients studied had completed questionnaires about whether they used underarm cosmetics during their lifetimes. Twenty-eight of the 35 (80%) had used them at some point, but seven of the 35 (20%) identified themselves as never users.
The findings suggest the parabens originated from a source other than underarm cosmetics, the researchers said.
"The presence of a chemical in the breast cannot be taken to imply causality per se, but it is nevertheless a prerequisite for consideration of any functional involvement in disease processes," the researchers wrote. "Measurement of individual chemicals in different locations across the breast in cases where a primary cancer has appeared does offer an approach that could eventually build up to provide a more detailed picture of the mechanisms by which environmental chemicals may enter and distribute across the breast."
Earn CME this spring at the HemOnc Today Breast Cancer Review & Perspective meeting to be held March 23-24, 2012 at the Hilton San Diego Bayfront. See details at HemOncTodayBreastCancer.com.
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