Possible Breast Carcinogen Found In Human Milk

December 16, 1998

Environmental pollutants that are known to cause cancer in rat mammary tissues are present in human breast milk, according to scientists in Canada. It is the first time that aromatic amines (AAs), which are used in many industrial processes, have been detected in human milk.

Researchers are not yet sure of the implications of the finding, saying it needs further investigation, but expressed concern that the substances may be a cause of breast cancer as well as a risk to nursing infants. They stress that the nutritional benefits of breast- feeding still outweigh the risks.

The finding is explained in the web edition of the peer-reviewed journal Chemical Research in Toxicology, published by the American Chemical Society -- the world's largest scientific society. It will appear in the print version of the journal on Dec. 21.

"Chronic exposure of the general population to AAs is a matter of public health importance," write P. David Josephy and Lillian DeBruin from the University of Guelph along with Janusz B. Pawliszyn at the University of Waterloo. "The presence of AAs in human milk implies that breast ductal epithelial cells, the target of mammary carcinogens, are also exposed."

AAs are used in the production of plastics, dyes, pesticides, and pharmaceuticals. Environmental sources for AAs include in industrial waste, air and water pollution, tobacco smoke, and some foods.

The study tested milk samples from 31 lactating mothers living near Guelph in Ontario, none of whom reported occupational exposure to AAs. All of the samples contained levels of AAs ranging from less than 0.01 to 7.44 parts per billion. Surprisingly, levels did not vary between smokers and non-smokers. Finding one particular AA, o-toluidine, may be of special significance because it is known to induce mammary tumors in female rats.

"We need to discover the major sources of these exposures," says Josephy. "Control of such exposures might ultimately help to lessen breast cancer risk, and possibly the risk of some other cancers."

Also troubling is the possibility that infants are being exposed to carcinogens through breast milk. However, Josephy adamantly adds, "Our results should in no way be taken to discourage breast-feeding, which has great health benefits for babies regardless of these trace contaminants."

The scientists plan to broaden their research to include women in other geographical areas. Previous studies have shown large variations in the breast cancer incidence, with especially high rates in the industrialized northeastern United States.

This research was supported by the Canadian Breast Cancer Foundation.
A nonprofit organization with a membership of more than 155,000 chemists and chemical engineers, the American Chemical Society publishes scientific journals and databases, convenes major research conferences, and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.

American Chemical Society

Related Breast Cancer Articles from Brightsurf:

Oncotarget: IGF2 expression in breast cancer tumors and in breast cancer cells
The Oncotarget authors propose that methylation of DVDMR represents a novel epigenetic biomarker that determines the levels of IGF2 protein expression in breast cancer.

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.

Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.

Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.

More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.

Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.

Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.

Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.

Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.

Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.

Read More: Breast Cancer News and Breast Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.