A handheld “pen” can detect cancer cells within seconds, speeding up diagnosis and helping surgeons more accurately remove tumors, researchers reported Wednesday. The probe works in real time, and is at least as accurate as removing a tissue sample and sending it to a pathologist, the team at the University of Texas at Austin reported. The pen uses a little drop of water to make the analysis and doesn’t require any cutting of tissue, the team reported in the journal Science Translational Medicine. They hope it can help make for less invasive surgery that gets every piece of tumor while also leaving behind as much healthy tissue as possible. "If you talk to cancer patients after surgery, one of the first things many will say is 'I hope the surgeon got all the cancer out,' " Livia Schiavinato Eberlin, an assistant professor of chemistry who led the work, said in a statement. "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." The team designed the pen and programmed a mass spectrometer to detect compounds that make lung, thyroid, ovary and breast tumors different from healthy tissue. They said it was accurate 96 percent of the time. "Any time we can offer the patient a more precise surgery, a quicker surgery or a safer surgery, that's something we want to do," said James Suliburk, head of endocrine surgery at Baylor College of Medicine, who worked with the team. "This technology does all three. It allows us to be much more precise in what tissue we remove and what we leave behind.” The team tested their pen on more than 250 samples of human tumors, calibrating the molecular signature of each type of tumor. Tumor cells have different activity than normal cells do, and researchers have been working for decades to use mass spectrometry to try to identify those differences quickly. "Cancer cells have dysregulated metabolism as they're growing out of control," Eberlin said. "Because the metabolites in cancer and normal cells are so different, we extract and analyze them with the MasSpec Pen to obtain a molecular fingerprint of the tissue “It allows