New Laser To Find Cancers

The blood transports cancer cells to other parts of our body, and researchers have now developed a new kind of laser that can find and zap those tumor cells from the outside of the skin. Livescience has written an article about this new diagnostic tool.

This tool may be in the future as a commercial diagnostic tool, but the laser is up to 1,000 times more sensitive than the current methods that are now used to detect tumor cells in the blood. This was recently reported by the researchers in the journal Science Translational Medicine.

Blood samples are typically taken to test for cancer spread but they often fail to find tumor cells, even if they are present in a single sample and the patient has an easy form of cancer, says senior author Vladimir Zharov, director of the nanomedicine center at the University of Arkansas for Medical Sciences. It means there’s a high concentration of circulating tumor cells in the blood if the tests come back positive. This means cancer has likely spread widely to other organs and it quite often means it’s too late to effectively treat the patients.

Zharov and his team came up with the idea of an alternate and noninvasive method to test larger quantities of blood that has greater sensitivity. It was tested in the lab and then on animals and was then brought to clinical trials in humans. The technology uses pulses of laser light on the outside of the skin to heat up cells in the blood. This technology is called the Cytophone and only heats up melanoma cells and not healthy ones. These cells carry a dark pigment called melanin that absorbs the light. The Xylophone uses an ultrasound technique to detect the teensy, tiny waves that are emitted by this heating effect.

The technology was tested on 28 light-skinned people with melanoma and on 19 healthy volunteers without melanoma. The laser was shone onto the patients’ hands and found that within 10 seconds to 60 minutes the technology could identify the circulating tumor cells in 27 of 28 of the volunteers.

There were no false positives on the healthy volunteers and no safety concerns or side effects caused. After the treatment, the team also found the cancer patients had fewer circulating tumor cells. The laser beam seemed able to destroy the cancer cells even at low energy. As the melanin absorbs the heat, the water around the melanin inside the cell begins to evaporate, producing a bubble that expands and collapses, mechanically destroying the cell. The goal is by killing these cells, they can help prevent the spreading of metastatic cancer, while still being harmless to other cells. The device hasn’t been tested yet on darker-skinned people with higher levels of melanin, but only a very small percentage of African Americans get melanomas.

They hope to expand the technology to find circulating tumor cells released by cancers other than melanoma. They would need to inject the patients with specific markers or molecules that would bind to these cells so they can be targeted by the laser as other cells do not carry melanin. This could work on human breast cancer cells as indicated so far in the lab.

Dr Fredda Branyon