FRIDAY, April 6, 2007 (HealthDay News) -- A treatment-induced growth factor called TGF-beta contributes to the progression of advanced cancer, U.S. researchers report.
In patients with advanced cancer, anti-tumor therapies work only partially or not at all, and tumors continue to grow following treatment, says a team at Vanderbilt-Ingram Cancer Center in Nashville, Tenn.
In tests with mice with metastatic breast cancer, the scientists found that radiation and chemotherapy treatments for cancer increased circulating levels of TGF-beta, circulating cancer cells, and tumor metastases.
The scientists also found that blocking TGF-beta in the mice prevented tumor metastases, which suggests that the use of TGF-beta inhibitors in combination with primary cancer therapies may benefit patients.
The study is published in the May issue of the Journal of Clinical Investigation.
"We wondered ... if TGF-beta induced by anti-cancer therapies can serve as a survival signal for tumor cells, thus allowing them to withstand therapy and later recur," and this study shows that this appears to be the case, research team leader Dr. Carlos Arteaga, professor of medicine and cancer biology, and director of the Vanderbilt-Ingram Breast Cancer Program, said in a prepared statement.
Several TGF-beta inhibitors are currently in early stage clinical trials.
"It probably isn't just TGF-beta that is having this effect. There are other growth factors and cytokines that have been reported to increase in response to radiation, chemotherapy and surgery, and some of these could also be tumor survival and prometastatic signals. TGF-beta may be just the tip of the iceberg," Arteaga said.
The U.S. National Cancer Institute has more about cancer.