New development in prediction and treatment of breast cancer

07/Oct/2006: A new discovery could help scientists, to effectively predict breast cancer outcomes and to understand how the cancer cells develop and grow within the body.

Richard Cote and his colleagues at the Keck School of Medicine at the University of Southern California studied a small group of breast cancer patients in the early-stage of the disease. These patients did not have any tumors in their bodies but had breast cancer cells in their bone marrow. The researchers were not sure whether these cells in their bone marrow, were primary tumor cells with short life-spans or breast cancer stem cells, which can reproduce continuously, creating new tumors.

Using innovative staining techniques, the research team discovered that cancer cells found in the bone marrow were breast cancer stem cells and their numbers were much higher than in solid tumors.

Cote said that more than 70% of the breast cancer cells found in the bone marrow was stem cells, which can lead to metastasis (metastasis is the spread of cancer from its primary site to other places of the body). He added that only 10% of the cancer cells in solid breast cancer tumors are stem cells.

Cote said that unlike the adult tumor cells, which are programmed to reproduce only a few times and then die, breast cancer stem cells can reproduce indefinitely and can spread to other tissues, elsewhere in the body and flourish there. Breast cancer stem cells can remain suppressed in the body for many years, increasing the risk of future metastatic diseases.

All the patients, who were examined under this study, were at a higher risk for metastases, because of the above factors, but such cases only comprise 20% of the entire early-stage breast cancer population. Cote said that the current therapies to breast cancer can cure almost 50% of the breast cancer patients, which means stems cells in more than half of the breast cancer patients are sensitive to therapies.

He added that, if the reasons behind why the breast cancer stem cells in some patients are resistant to therapies are established, then we may be able to prevent metastatic diseases in all breast cancer patients.

Larry Norton, chief of the breast cancer programs at Memorial Sloan – Kettering Cancer Centre in New York, appreciated Robert Cote and his team for their efforts in this study. He said that, if tumor-initiating breast cancer cells were prevented from forming tumors, then it could prove to be great advance in our ability to prevent and control breast cancer.

Cote said that bone marrow transplant techniques are not effective in treating early-stage breast cancer patients, as the marrow metastases spread the cancer cells to the other parts of the body. High-dose chemotherapy produced better results than bone marrow transplants, since it was able to reach all the cells and did not have any significant side effects, as in the case of bone marrow transplants.

Cote and his team are currently measuring breast cancer stem cells in the bone marrow, using a whole set of techniques, to understand how the stem cells respond to cancer therapies.

Further Reading
http://www.breastfit.com