Imagine breast cancer treatment with fewer side effects than today’s therapies. Now imagine treatment that works even better at keeping cancer away.
Doctors aren’t just imagining it — they’re trying new strategies that may do just that.
 Shiuan Chen (Photo by Markie Ramirez)
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City of Hope researchers are studying a combination of drugs meant to battle the most common forms of breast cancer: tumors fueled by the female hormone estrogen. They’ve paired up aromatase inhibitors, drugs that block production of estrogen in postmenopausal women, together with an investigational drug that specifically targets breast cancer cells.
Aromatase is scientist Shiuan Chen’s world. As he explains it, the substance aromatase naturally converts hormones called androgens into estrogen. That’s the main way women’s bodies make estrogen.
About 70 percent of breast cancers are hormone-dependent, requiring estrogen to survive and grow, said Chen, Ph.D., principal investigator on the study and co-leader of City of Hope’s Breast Cancer Research Program. Block or control levels of estrogen, and you go a long way toward fighting most breast cancers.
Enter aromatase inhibitors.
“Aromatase inhibitors are a type of breast cancer drug that work by drastically lowering estrogen levels in the body,” said Chen, who also directs City of Hope’s Division of Tumor Cell Biology. Chen studies the mechanism breast cancer cells use to control aromatase levels. His lab was one of three internationally to discover how breast cancer cells produce their own estrogen.
Physicians often prescribe aromatase inhibitors after initial breast cancer treatment to keep cancer from returning. Unfortunately, these drugs can produce side effects from severe joint pain to bone loss and fractures. Another drawback: Patients can become resistant to aromatase inhibitors.
Chen turned to another new drug that might help.
His previous research concluded that an investigational drug called LBH589, or panobinostat, inhibits aromatase expression in breast cancer cells while leaving healthy cells alone. Researchers believe that combining this new drug with aromatase inhibitors may help prevent side effects and drug resistance in the treatment of hormone-dependent breast cancer in postmenopausal women, because women will be able to take lower doses of the aromatase inhibitors.
The investigational drug may work through what scientists call epigenetics. That means it may silence certain important genes.
Chen wants to identify those silencing switches.
Laboratory studies also aim to understand the effectiveness of combination therapy in stopping estrogen production in breast cancer cells and in delaying resistance.
Tips for lowering breast cancer risk Odds are that one in eight women in the United States will develop breast cancer in her lifetime. But key lifestyle changes can help a woman lessen her chances. The American Cancer Society recommends limiting alcohol as well as fat intake, keeping a healthy weight and exercising regularly. Also, recent research suggests eating certain fruits and vegetables can lower risk. Mothers who breast feed for several months also lower their risk of breast cancer, and avoiding unnecessary hormone replacement therapy after menopause can help, as well. And, as always, consult with a health-care professional to help ensure your choices make the most sense for you. |
