Researchers in U.S have discovered that light could be a “promising” tool in the fight against cancer, without damaging the surrounding tissues. They described how a drug could be created which sticks to tumors, but is activated only when hit by specific waves of light.

In this study, researchers at the National Cancer Institute, Maryland, used an antibody, which targets proteins on the surface of cancerous cells. They then attached a chemical, IR700, to the antibody. IR700 is activated when it is hit by near infrared light. This wavelength of light can penetrate several centimeters into the skin.

To test the antibody-chemical combination, researchers implanted tumors, squamous cell carcinoma, onto the backs of mice. They were given the drug and exposed to near infrared light. The study revealed that "Tumor volume was significantly reduced… compared to untreated mice and survival of mice was significantly prolonged.

This selective killing minimizes damage to normal cells. The authors said “the combination was a promising therapeutic and diagnostic agent for the treatment of cancer."Although we observed no toxicity in our experiments, clinical translation of this method will require formal toxicity studies," they added.

Dr. Laura McCallum, Cancer Research UK's science communications officer, said the research was promising."Using antibodies or photodynamic therapy to specifically target cancer cells have both been successful for treating some cancers, so combining the two together is certainly an exciting plan. But it's important to remember that this research was done on mice, so it's much too early to tell if it will work on people with cancer.”