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
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
"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
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
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.