By Stephanie Stahl

PHILADELPHIA (CBS) —  Invisible cancer, it’s a killer.  Now local researchers have found a way to see what until now has been undetectable cancer.  3 On Your Side Health Reporter Stephanie Stahl has more on what’s being called a game changer.

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A special green glow could light up the future of cancer therapy.

“I feel like I’m a miracle woman, and I’m lucky,” said Francie Howat, who was diagnosed with lung cancer earlier this year.  The 65-year-old, a lifelong smoker, was scared and worried she wouldn’t be around to  watch her grandchildren grow up.  She decided to be part of a research trial at the Hospital of the University of Pennsylvania.

Surgeon Sunil Singhal, with Penn Medicine, says lung cancer is often surgically removed, but about 30 percent of the time invisible cancer cells are missed.  And they can become deadly.

“It’s something that’s not detectable,” said Dr. Singhal.

But now researchers have found a way to make the invisible visible with a special dye, used for other medical procedures.  It’s been engineered to accumulate in lung cancer cells and light up green, under infrared light.

“For the first time we actually have the ability to make tumors glow,” said Dr. Singhal.

Before the operation patients are injected with the dye.  Then during the surgery the light is turned on.  During Francie’s surgery, tissue that looked normal, and was clear on scans, was actually cancerous.

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“This looks perfectly normal, but there we found another spot glowing,” said Dr. Singhal.

If the lung cancer testing pans out, researchers are hoping they can formulate the dye to be able to find other cancers.

“It’s going to change the field.  It’s a paradigm shift for surgeons to be able to see things that we never did before.  It’s exciting,” said Dr. Singhal.

Left with a few scars that will heal, Francie, who lives in Tinicum Township, was able to avoid chemo and radiation.

And now she’s dancing with her grandchildren to celebrate as she recovers from a remarkably short stint with lung cancer.

“He said it would have killed me.  I think that’s laying it on the line.  I thinks it’s a miracle,” said Francie.

So far the green dye has only been tested on five lung cancer patients.  Results are promising.  Researchers are still tweaking the process and hope to expand the research soon.

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Penn Medicine’s Abramson Cancer Center Information-

Stephanie Stahl