Chemical Alterations

Understanding Alcohol’s Contribution to Breast Cancer Risk

EVERY DRINK MAY matter when it comes to breast cancer. Although there is considerable evidence linking alcohol consumption with breast cancer, most women are unaware, and research so far has not yet revealed how it causes breast cancer or who may be most at risk. With support from the John Fetting Fund for Breast Cancer Prevention, epigenetics expert and breast cancer survivor Cynthia Zahnow, Ph.D., hopes to shed new light and explore what role epigenetics may play.

Epigenetics is the study of chemical alterations that help control gene expression and, as a result, the behavior of cells. Zahnow and her Kimmel Cancer Center colleagues are among the leaders in cancer epigenetics, deciphering how these chemical alterations can turn genes on and off and contribute to cancer development.

Although alcohol consumption increases breast cancer risk for women of all ages, Zahnow says younger women may be most vulnerable because breast tissue is the most sensitive to environmental exposures from the start of menstruation until first pregnancy. She says it’s important to point out that it’s alcohol itself, not the type of alcoholic drink (beer, wine, whiskey, etc.) that is associated with breast cancer risk.

“It’s quite clear that the more alcohol a woman drinks and the younger she drinks contributes to a greater risk of breast cancer, but little is known about the underlying mechanism,” she says. “We want to understand specifically what amount of alcohol consumption increases risk. Is it one drink a week, or are other epigenetic or mutagenic hits required in addition to this to confer risk?”

As a member of what is considered among the best epigenetic programs in the world, Zahnow hopes this research will provide important information that could modify a person’s drinking behavior to help lower the risk of breast cancer. She wants to determine how much alcohol, if any, is safe for women. “This is an easily modifiable behavior,” she says, and she wonders, “As a breast cancer survivor, should I be drinking at all? And, what about my daughter who is a senior in college? I also want to know if it’s safe for her to drink, and how much alcohol is too much.”

Zahnow and graduate student Cassie Holbert will study normal breast cells to see how their behavior changes when exposed to alcohol. For example, does alcohol cause breast cells to become more invasive, growing into ducts where they should not be? She will also examine breast cancer cells obtained from women who drink alcohol to look for similarities in epigenetic changes. “Our long-term goal is to come up with an alcohol induced epigenetic profile that could help to identify women who may be most at risk for developing breast cancer,” says Zahnow.

Zahnow hopes her research will provide important information women can use to make informed decisions that could reduce their breast cancer risk.