Study using light reveals breast tumor oxygen status

Bioengineers at Duke University in Durham, N.C., have developed a light-based system that provides information about tumor oxygen levels while the tumor is still in vivo. This needle-based technique can provide pathologists with biological specifics of the tumor and help oncologists choose treatment options that would be most effective for that individual patient, according to the researchers.

The new system, based on diffuse reflectance spectroscopy, gives important clues about the tumor by interpreting how the light is either reflected back from the tumor or absorbed.

Oxygen status is important since past studies have shown that low levels of oxygen, or hypoxia, are more often associated with malignant tissue than healthy normal tissue, said lead author J. Quincy Brown, a fourth-year post-doctoral fellow at the Pratt School of Engineering.

Tumors that thrive in these low-oxygen environments tend to be more difficult to treat, Dr. Brown’s group explained in Cancer Research (69:2919-2926, 2009).

The researchers enrolled 35 breast cancer patients scheduled to undergo surgery. Before the surgery, normal, UV-visible light was directed through a needle at the surface of the tumor while it was still in the breast. Their main target was blood and its hemoglobin.

“Our system measured how the light was either absorbed by the hemoglobin, which gave us an optical fingerprint of the oxygen status of the tumor,” Mr. Brown said. “This fingerprint can give clues about which form of therapy, chemotherapy, radiation, surgery, might be the most effective for that particular tumor.”