University of Adelaide researchers have developed an optical fiber probe that distinguishes breast cancer tissue from normal tissue—potentially allowing surgeons to be much more precise when removing breast cancer.

The newly developed probe operates on the principle that cancer tissue has a more acidic environment than normal cells, generating a greater amount of lactic acid as a byproduct of its aggressive growth. A pH indicator embedded in the tip of the optical probe emits a different color of light depending on the acidity. A miniature spectrometer on the other end of the probe analyzes the light and therefore the pH.

Current surgical techniques to remove cancer lack a reliable method to identify the tissue type during surgery. Image credit: Pixabay. “How we see it working is the surgeon using the probe to test questionable tissue during surgery," says project leader Dr. Erik Schartner, postdoctoral researcher in the Centre of Excellence for Nanoscale BioPhotonics at the University of Adelaide. "If the readout shows the tissues are cancerous, that can immediately be removed. Presently, this normally falls to post-operative pathology, which could mean further surgery."

Current surgical techniques to remove cancer lack a reliable method to identify the tissue type during surgery, relying on the experience and judgment of the surgeon to decide how much tissue to remove. Because of this, surgeons often perform "cavity shaving," which can result in the removal of excessive healthy tissue. At other times, some cancerous tissue will be left behind.

“This is quite traumatic to the patient and has been shown to have long-term detrimental effects on the patient’s outcome,” says Schartner.

The researchers believe the new probe could help prevent the need for follow-up surgery, currently required for the 15%-20% of breast cancer surgery patients in which not all the cancer is removed.

Schartner's team has a portable demonstration unit and is doing further testing with the aim of beginning clinical studies in the near future.