Breast milk may provide a personalized screen of breast cancer risk

(Press-News.org) ORLANDO, Fla. — Breast cancer risk can be assessed by examining the epithelial cells found in breast milk, according to preliminary study results presented at the AACR 102nd Annual Meeting 2011, held April 2-6.

This screening method has the potential to provide a personalized assessment of breast cancer risk, said lead researcher Kathleen F. Arcaro, Ph.D., associate professor of veterinary and animal sciences at the University of Massachusetts Amherst. Given that roughly 80 percent of women give birth, this screen would also cover a large percentage of the female population.

Arcaro and colleagues collected breast milk samples from about 250 women who were scheduled for or who had a breast biopsy. The women submitted fresh samples, which were processed within 24 hours of expression; they provided samples from both breasts.

The researchers recruited about 90 percent of their study population from the Love/Avon Army of Women, which registers women who are willing to participate in breast cancer research. The American Association for Cancer Research is the scientific partner in this effort.

Once researchers received the samples, they isolated the epithelial cells (the potentially cancerous cells) in the breast milk. Then they isolated the DNA to look for epigenetic signals (attachment of methyl groups to DNA), which are the signals that tell the body those genes that should be expressed. These signals were then compared with breast cancer risk assessed using the biopsy results.

Arcaro and colleagues analyzed three genes: RASSF1, GSTP1 and SFRP1. "More than 35 genes have been shown to be methylated in breast cancer," she said.

Of the 104 women with a non-proliferative (low-risk) lesion, results showed no difference in the average epithelial DNA methylation of their biopsied breast vs. non-biopsied breast for RASSF1 and GSTP1. For SFRP1, however, the average methylation was higher in the biopsied breast. Importantly, among the women whose biopsies revealed cancer, there was a significant increase in average RASSF1 methylation in the biopsied breast vs. non-biopsied breast. Although the sample size in this study is small, "it's sufficient to tell us that we can use the cells in breast milk to assess breast cancer risk," Arcaro said, and additional studies are needed to expand the number of genes. Long-term studies are currently underway with about 80 percent of the original participants enrolled in follow-up.

Arcaro hopes that someday every woman who delivers a baby in a hospital will be screened for breast cancer via breast milk. "We'll take a little sample of colostrum, and we'll tell her how her breasts are doing," she said. "It's totally noninvasive, potentially inexpensive and really accurate."

### This research will be presented at an AACR press conference on Monday, April 4 at 8:30 a.m. ET in room W313 of the Orange County Convention Center. Reporters who cannot attend in person can participate using the following information:

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Press registration for the AACR 102nd Annual Meeting 2011 is free to qualified journalists and public information officers: http://www.aacr.org/PressRegistration

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The mission of the American Association for Cancer Research is to prevent and cure cancer. Founded in 1907, the AACR is the world's oldest and largest professional organization dedicated to advancing cancer research. The membership includes 33,000 basic, translational and clinical researchers; health care professionals; and cancer survivors and advocates in the United States and more than 90 other countries. The AACR marshals the full spectrum of expertise from the cancer community to accelerate progress in the prevention, diagnosis and treatment of cancer through high-quality scientific and educational programs. It funds innovative, meritorious research grants, research fellowships and career development awards. The AACR Annual Meeting attracts more than 18,000 participants who share the latest discoveries and developments in the field. Special conferences throughout the year present novel data across a wide variety of topics in cancer research, treatment and patient care. Including Cancer Discovery, the AACR publishes seven major peer-reviewed journals: Cancer Research; Clinical Cancer Research; Molecular Cancer Therapeutics; Molecular Cancer Research; Cancer Epidemiology, Biomarkers & Prevention; and Cancer Prevention Research. AACR journals represented 20 percent of the market share of total citations in 2009. The AACR also publishes CR, a magazine for cancer survivors and their families, patient advocates, physicians and scientists.