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A yellow-brick path to lung cancer

New research may take the guesswork out of determining tumor margins.

By Robin Tricoles

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Did they get everything? That’s often the question on patients’ minds following cancer surgery. But the answer isn’t always clear. Distinguishing cancer cells from healthy ones during surgery can prove difficult, if not impossible. Sometimes lesions are detected only postoperatively, leading to more surgery down the line.

Currently, surgeons rely on vision and touch to detect tumors during surgery. “There is still no good way to determine a tumor’s margins,” says Shuming Nie, director of cancer nanotechnology programs at Emory’s Winship Cancer Institute. “It’s still guesswork.”

But Nie and colleagues at the Emory-Georgia Tech Nanotechnology Center and the University of Pennsylvania are hoping to take the guesswork out of identifying cancer cells while the patient is still in the operating room. In ongoing research—recently bolstered by a $7 million, five-year grant from the NIH—they have developed fluorescent nanoparticle probes that make it possible to detect the tumor margins of lung cancer cells during surgery.

A lung cancer cell is about 10 to 15 micrometers, too small to be seen with the naked eye. But when the nanoparticle probes bind to cancer cells, the cells glow. Surgeons can then detect the light they emit by using a handheld device (called a SpectroPen) coupled to an imaging system. The device detects fluorescent dyes and light-reflecting nanoparticles.

Developed by Nie, these particles consist of polymer-coated gold, which is bound to a dye and an antibody, causing them to stick better to the outside of tumor cells than to healthy cells. The gold amplifies the signal from the dye, which is then picked up by the SpectroPen.

Specifically, the approach will help surgeons distinguish tumor margins, identify diseased lymph nodes, and pinpoint cells that have spread beyond the original tumor.

“Having these capabilities can make a major impact on reducing recurrence rates of cancer after surgery,” says Nie.

The technology may be effective in identifying many types of solid tumors, such as breast lesions, but the researchers chose to focus first on lung cancer because of its low survival rate. Already, they have shown that SpectroPen in combination with the gold nanoparticles works well to detect lung cancer tumors in mice. The grant will allow them to test the nanotechnology and cancer detection instruments on dogs with naturally occurring tumors at the University of Georgia and eventually in humans in a first-ever clinical trial for patients with lung cancer at the University of Pennsylvania.

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