Common Household Chemical Could Raise Breast Cancer Risk

Common Household Chemical Could Raise Breast Cancer Risk
THURSDAY, Dec. 6 (HealthDay News) -- A chemical found in manyplastic products used in households caused accelerated breast developmentand genetic changes in newborn female lab rats, a condition that mightpredispose the animals to breast cancer later in life, a new studysays.
Butyl benzyl phthalate (BBP) is commonly used to soften polymers andplastics. It's found in everything from plastic pipes, vinyl floor tilesand carpet backing to lipstick. BBP has also been found to be an endocrinedisruptor, which mimics the effect of hormones. Endocrine disruptors areknown to damage wildlife and have also been implicated in reduced spermcounts and neurological problems in humans, the researchers said.
"Our study is the first one demonstrating that exposure to thiscompound (BBP) soon after birth results in alterations in the expressionof genes present in the mammary gland," said lead researcher Dr. JoseRusso, a breast cancer expert at the Fox Chase Cancer Center, inPhiladelphia.
The findings are important, Russo said, because the researchers arestudying the lifetime effect of BBP on the mammary gland, long before itstarts developing under the influence of the hormones of puberty, and thepotential implications on humans.
Because of lasting genetic changes in the breast, exposure to BBP couldincrease the risk for developing breast cancer later in life, Russosaid.
"To prevent breast cancer in adulthood, it is necessary to protect boththe newborn child and the mother from exposure to this compound that hasan estrogenic effect and could act as an endocrine disruptor," headded.
For the study, Russo's team fed lactating rats BBP, which theiroffspring absorbed through breast milk. The rat pups received levels ofthe chemical equivalent to the U.S. Environmental Protection Agency's safedose limit for humans, according to the report in the Dec. 5 online issueof BMC Genomics.
The researchers found that BBP affected characteristics of the femaleoffspring of the rats, such as more rapid breast development and changesin the genetic profile of the mammary glands. While these effects wore offafter exposure to BBP was stopped, the changes caused by the chemicalmight have an effect later in life, the researchers said.
"Our original observations are that the genomic changes induced by BBPoccur very early in life, and they could result in significantmodifications in the risk of the mammary gland to develop cancer later onin life," Russo said.
Russo said he and his colleagues are currently evaluating how changesin gene expression caused by BBP respond to cancer-causing chemicals givento adult rats.
"We are also studying the effects of exposure to BBP before birth. Inaddition, we are following a cohort of girls entering puberty fordetermining the tempo of breast development and their first menstrualperiod and associating these events with exposure to environmental agentssuch as BBP," Russo said.
One expert said scientists are only beginning to learn how many genesare affected by exposure to chemicals early in life.
"The early exposure to BBP altered breast development and may thereforealter the susceptibility to breast cancer," said Dr. Ted Schettler,science director at the Science and Environmental Health Network, in Ames,Iowa.
Schettler thinks people need to be aware of the possible effects ofchemicals on genes during early life, and how these changes can influencesusceptibility to disease in adulthood.
"People are finally getting the idea that early life events can matterlater in life," Schettler said. "When people see that commonly encounteredenvironmental agents like BBP can cause genetic changes, it's of publichealth interest."
However, Dr. Jonathan Borak, a clinical professor of environmentalmedicine at Yale University School of Public Health, said there's noevidence that exposure to BBP increases the risk of breast cancer.
"To date, studies have failed to find an association between BBP andbreast cancer," Borak said. "This study doesn't add specific informationon breast cancer and environmental interactions."
Efforts to reach the American Chemistry Council, a chemical industrygroup, for comment on the study were unsuccessful.
In October, California adopted a law that will ban trace amounts of BBPin toys and baby products such as teething rings, according to publishedreports.
And in March, a study published in the journal Environmental HealthPerspectives suggested that exposure to phthalates could be fuelingthe obesity epidemic by contributing to abdominal obesity and insulinresistance in men.