Breast Cancer stem cells are resistant to radiation therapy!

HealthDay News: Breast cancer stem cells, a type of cell that scientists have recently discovered is difficult to kill, may be especially resistant to radiation therapy, a new study suggests.

In fact, the radiation can even increase the growth of these stubborn stem cells, report researchers from the University of California, Los Angeles, David Geffen School of Medicine.

"This population of stem cells is more radiation-resistant than are non-stem cells," said Dr. Frank Pajonk, an assistant adjunct professor of radiation oncology at UCLA and corresponding author on the study. "We are the first to report this."

Radiation treatment involves exposure to high-energy rays or particles that destroy cancerous cells. It is often recommended after surgery for breast cancer, according to the American Cancer Society.

Pajonk and his colleagues exposed breast cancer stem cells and "normal" breast cancer cells to either single or multiple doses of radiation. More of the stem cells, also called cancer-initiating cells, lived through the radiation than did the other breast cancer cells.

One good example, according to Pajonk: While 46 percent of the stem cells survived treatment with 2 Gray of radiation (a dose typically used for breast cancer treatment), only 20 percent of normal breast cancer cells did.

Then, the team simulated clinical treatment that is interrupted -- a challenge that Pajonk and other health-care providers face when patients don't make all their scheduled appointments due to fatigue, inconvenience or other factors. Pajonk and his colleagues suspect this reduces the effectiveness of radiation, and the study suggests they are correct.

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