Researchers discover reason why breast cancer cells become drug resistant

"There is evidence that patients with a lot of IL-6 tend to do poorly. What we found now is that in many of the Herceptin-resistant breast cancers, the IL-6 inflammation loop is driving the cancer stem cell," says lead study author Hasan Korkaya, D.V.M., Ph.D., research assistant professor of internal medicine at the U-M Medical School.

The researchers found that blocking the IL-6 inflammatory loop almost completely blocked the cancer and the stem cells. Mice treated with the IL-6 blocker along with Herceptin immediately after the cancer developed never became resistant to Herceptin.

IL-6 is known to play a role in inflammatory diseases such as rheumatoid arthritis, as well as obesity and cancer. Tocilizumab, a drug that targets this protein, is approved by the U.S. Food and Drug Administration to treat rheumatoid arthritis.

The researchers are developing a clinical trial to test the IL-6 blocker along with Herceptin. That trial will likely open early in 2013.

Source: University of Michigan Comprehensive Cancer Center