Cancer Stem Cells and Breast Cancer

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Stem Cells For Dummies

Lawrence S. B Goldstein, PhD

Director, University of California, San Diego Stem Cell Initiative

Meg Schneider

Award Winning Journalist

The traditional treatments for cancer are surgery to remove as many cancer cells as possible, and chemotherapy and raditon to zap any cancer cells that remain in the body. But if cancer stem cells have the same kinds of defenses that normal cells do, they may be able to pump out chemicals designed to kill them and send out enzymes to get rid of the ROS (reactive oxygen species) generated by radiation treatments.

As it turns out, that may be exactly what happens in cancer stem cells-or at least in some kinds of them. Some researchers have discovered evidence that the cancer stem cells in some cancers, including breast cancer, repair DNA damage more readily after radiation treatment than other types of cancer cells do. Researchers have recorded similar results in tests on human head and neck cancers, too.

These stem cell defense mechanisms may explain why traditional cancer therapies can knock down cancer but often can't knock it out. The therapies that are most effective at killing nonstem cancer cells apparently deal only glancing blows-if that-to cancer stem cells. It's like the archetypical alien invasion movie, where mankind's most powerful weapons can't penetrate the mother ship's force field.

The traditional way of tackling cancer (after surgery, and sometimes in lieu of surgery) has been to kill every abnormal cell in sight that's dividing-while trying not to kill every normal cell in the patient that's dividing. It's not an easy trick to pull off, because the methods that are lethal to most cancer cells are also, unfortunately, lethal to nearly all normal cells.