Cutting edge: Detecting cancer tissue in 10 seconds

The invention of a team of scientists and engineers at The University of Texas at Austin is set to revolutionise the diagnostic method for rapidly and accurately identifying cancerous tissue during surgery. It would deliver results in about 10 seconds which is 150 times faster than the existing technology. The cutting edge handheld instrument known as The MasSpec Pen provides surgeons with exact diagnostic information about which tissue to cut or preserve. This will help in treatment and reduce the scope of recurrence of cancer.

The research is described in the September 6 edition of the journal Science Translational Medicine. “If you talk to cancer patients after surgery, one of the first things many say is, ‘I hope the surgeon got all the cancer out’,” says Livia Schiavinato Eberlin, assistant professor of chemistry at UT Austin who designed the study and led the team. “It’s just heartbreaking when that’s not the case. But our technology could vastly improve the odds that surgeons really do remove every last trace of cancer during surgery.” Frozen Section Analysis, the existing high-tech method for identifying cancers and determining the boundary between cancer and normal tissue during surgery, is slow and at times inaccurate. The risk of infection and negative effects of anaesthesia is more as it takes 30 plus minutes for pathologists to prepare and interpret each sample.

How it Works
Living cells, whether they are healthy or cancerous, produce small molecules called metabolites. These molecules are involved in generating energy and other useful functions like removing toxins. Each type of cancer produces a unique set of metabolites and other biomarkers that act as fingerprints. “Cancer cells have dysregulated metabolism as they are growing out of control. Because the metabolites in cancer and normal cells are so different, we extract and analyse them with the MasSpec Pen to obtain a molecular fingerprint of the tissue,” says Eberlin.

The molecular fingerprint obtained by the MasSpec Pen from an uncharacterised tissue sample is instantaneously evaluated by software called a statistical classifier, trained on a database of molecular fingerprints that Eberlin and her colleagues gathered from 253 human tissue samples. The samples included both normal and cancerous tissues of the breast, lung, thyroid and ovary. When the MasSpec Pen completes the analysis, the words ‘Normal’ or ‘Cancer’ automatically appear on a computer screen. For certain cancers, such as lung cancer, the name of a subtype might also appear.

In tests on tissues removed from 253 human cancer patients, the MasSpec Pen took about 10 seconds to provide a diagnosis and was more than 96 per cent accurate. The team expects to start testing this new technology during oncologic surgeries in 2018. “Tumour usually spreads through the lymphatic system and blood stream. Through tumour seeding, cells get deposited in various organs and they grow as secondaries. How far the new technology is going to arrest this will be interesting to see,” said Dr R. Sivarmakrishnan, Professor of Radiotherapy, TD Medical College, Alappuzha.

He says the technology might help in enhancing recovery especially in cases where tumours are detected completely early on. “In cases of advance stage where primary surgery may not be possible, chemotherapy and radiotherapy might be needed to reduce the tumour size. How will this technology work in such cases,” Dr Sivaramakrishnan asked. Physicians can operate the disposable handheld device easily. It requires simply holding the pen against the patient’s tissue, triggering the automated analysis using a foot pedal, and waiting a few seconds for a result. Meanwhile, the pen releases a drop of water on to the tissue, and small molecules migrate into the water. Then the device drives the water sample into an instrument called a mass spectrometer, which detects thousands of molecules as a molecular fingerprint.

“If their claim comes to be true then it will be a great achievement and would definitely revolutionise cancer treatment. As of now, the patient has to undergo a series of tests including CT scan, MRI, PET scan to detect cancerous cells. Even after surgery it is difficult to locate the margins,” says Dr Sanil Kumar, a Kochi-based health activist connected with the Justice Krishna Iyer Movement. He says the present study is only on 253 patients which is not enough. The procedure needs to be tested on thousands of people through extensive trials and needs to get permission from mandatory regulatory bodies before receiving scientific acceptance. There are many phases of research and trial left, he added.

“When designing the MasSpec Pen, we made sure the tissue remains intact by coming into contact only with water and the plastic tip of the MasSpec Pen during the procedure,” says Zhang. “The result is a biocompatible and automated medical device that we are so excited to translate to the clinic very soon.” Funding for this research was provided by UT Austin through the start up funds to Eberlin, as well as by the National Cancer Institute of the National Institutes of Health and the Cancer Prevention Research Institute of Texas. An interdisciplinary team integrating the fields of chemistry, engineering and medicine accomplished the research.