LONDON — Surgeons may have a new way to smoke out cancer.
An experimental surgical knife can help surgeons make sure they've removed all of the cancerous tissue, doctors reported Wednesday. Surgeons typically use knives that heat tissue as they cut, producing a sharp-smelling smoke. The new knife analyzes the smoke and can instantly signal whether the tissue is cancerous or healthy.
Usually, surgeons have to send the tissue to a lab and wait for the results.
Dr. Zoltan Takats of Imperial College London suspected that the smoke produced during cancer surgery might contain some important cancer clues. So he designed a "smart" knife hooked up to a refrigerator-sized mass spectrometry device on wheels that analyzes the smoke from cauterizing tissue.
The smoke picked up by the smart knife is compared to a library of smoke "signatures" from cancerous and noncancerous tissues. Information appears on a monitor: Green means the tissue is healthy, red means cancerous and yellow means unidentifiable.
To make sure they've removed a tumor, surgeons now send samples to a laboratory while the patient remains on the operating table. It can take about 30 minutes to get an answer in the best hospitals.
If some cancerous cells remain, patients may need to have another surgery or undergo chemotherapy or radiation treatment.
The new knife "looks fabulous," said Dr. Emma King, a head and neck cancer surgeon at Cancer Research U.K. who was not connected to the project. The smoke contains broken-up bits of tumor tissue, and "it makes sense to look at it more carefully," she said.
The new knife and its accompanying machines were made for about $380,000, but scientists said the price tag would probably drop if the technology is commercialized.
The most common treatment for cancers involving solid tumors is removing them in surgery. In the U.K., one in five breast cancer patients who have surgery will need further operations to get rid of the tumor entirely.
Scientists tested the new knife at three hospitals between 2010 and 2012. Tissue samples were taken from 302 patients to create a database of which kinds of smoke contained cancers, including those of the brain, breast, colon, liver, lung and stomach.
That information was then used to analyze tumors from 91 patients; the smart knife correctly spotted cancer in every case. The study was published Wednesday in the journal Science Translational Medicine.