Drug Fights Resistant Breast Cancer
Reported December 14, 2009
(Ivanhoe Newswire) — A new drug cocktail might be the right mix to fight breast cancer after it becomes resistant to standard therapy.
The standard treatment for breast cancer is anti-hormonal medicines, such as aromatase inhibitors (AIs), which lower the amount of estrogen in the body. Over time, however, the cancer figures out a way to thrive without the estrogen. The new strategy to fight this resistance combines an aromatase inhibitor with sorafenib, an FDA-approved oral medication used to treat liver and kidney cancers.
“We believe the sorafenib might disrupt the machinery created by the tumor to grow without the estrogen,” presenting author Claudine Isaacs, M.D., clinical director of breast cancer program at Georgetown Lombardi Comprehensive Cancer Center, was quoted as saying.
“After the machinery is destroyed, the aromotase inhibitor can do its work again,” she explained. “We’re already seeing some encouraging responses to this approach.”
The study involved 35 post-menopausal women with metastatic breast cancer resistant to aromotase inhibitors. The women continued taking an aromotase inhibitor for the study, but they also took sorafenib. Twenty percent of the women had a complete or partial response, including those who had stable disease for at least 6 months.
Isaacs said this finding suggests that sorafenib is acting to reverse resistance to AIs, as this type of response would not have been expected with either sorafenib alone or with continuing the AI. She concluded, “To manage breast cancer long term, it’s apparent that we may need to continually switch drugs to keep up with how a cancer evolves and evades each approach.”
SOURCE: Presented at the CTRC-AACR San Antonio Breast Cancer Symposium, December 9 – 13, 2009