How to find hidden cancers? Doctors try glowing dyes

PHILADELPHIA » It was an ordinary surgery to remove a tumor — until doctors turned off the lights and the patient’s chest started to glow. A spot over his heart shined purplish pink. Another shimmered in a lung.

They were hidden cancers revealed by fluorescent dye, an advance that soon may transform how hundreds of thousands of operations are done each year.

Surgery has long been the best way to cure cancer. If the disease recurs, it’s usually because stray tumor cells were left behind or others lurked undetected. Yet there’s no good way for surgeons to tell what is cancer and what is not. They look and feel for defects, but good and bad tissue often seem the same.

Now, dyes are being tested to make cancer cells light up so doctors can cut them out and give patients a better shot at survival.

With dyes, “it’s almost like we have bionic vision,” said Dr. Sunil Singhal at the University of Pennsylvania. “We can be sure we’re not taking too much or too little.”

The dyes are experimental but advancing quickly. Two are in late-stage studies aimed at winning Food and Drug Administration approval. Johnson & Johnson just invested $40 million in one, and federal grants support some of the work.

“We think this is so important. Patients’ lives will be improved by this,” said Paula Jacobs, an imaging expert at the National Cancer Institute. In five or so years, “there will be a palette of these,” she predicts. MAKING CELLS GLOW Singhal was inspired a decade ago, while pondering a student who died when her lung cancer recurred soon after he thought he had removed it all. He was lying next to his baby, gazing at fluorescent decals.

“I looked up and saw all these stars on the ceiling and I thought, how cool if we could make cells light up” so people wouldn’t die from unseen tumors, he said.

A dye called ICG had long been used for various medical purposes. Singhal found that when big doses were given by IV a day before surgery, it collected in cancer cells and glowed when exposed to near infrared light. He dubbed it TumorGlow and has been testing it for lung, brain and other tumor types.