PHILADELPHIA - Gloria Correa has tried all the standard weapons in her war against cancer: chemotherapy, radiation, and finally surgery.

But when a surgeon opened her up last fall to cut out the deadly tumor that was squeezing her bile duct, he saw that it had engulfed nearby arteries. It was impossible to remove.

Now Correa is trying a gentler-sounding approach at Thomas Jefferson University Hospital: light.

First she was infused with medicine that made the tumor cells light-sensitive. Two days later, physician David Loren carefully threaded a flexible fiber down through her intestines and bathed the cancerous mass with the glow of a red laser.

Called photodynamic therapy, the technique represents part of medicine's continuing quest for treatments that target tumors while sparing the rest of the body from unpleasant side effects. Though far more common in Europe, this light-based therapy is gaining proponents in the United States, where it has long been approved for treating certain lung and skin cancers.

Loren is among the researchers who seek to expand its use. He is participating in a University of Virginia-led effort to gain approval to use it on bile-duct tumors.

Separately, researchers at University of the Sciences in Philadelphia are using the technique to combat prostate cancer in lab animals.

Correa, 54, of Langhorne, feels like something of a lab animal herself. She is among just a handful of U.S. patients who have gotten the treatment for bile-duct cancer (cholangiocarcinoma), and at first she was a little hesitant.

So were her two sons, both in their 20s.

"They asked me if I was going to glow in the dark," she said, before undergoing the first of several treatments last month.

No, but the therapy does have one significant side effect:

The medicine that makes the tumor cells sensitive to light has a similar effect on the rest of the body. Regular cells excrete the medicine more quickly than do cancer cells, yet the kind of drug Correa received still had a fairly long impact. She would have to stay away from bright light for several weeks, or else suffer a bad sunburn.

So when Correa arrived at Jefferson for her first encounter with the laser, she wore a floppy, wide-brimmed hat and dark sunglasses.


The bile duct plays a key role in digestion, ferrying bile salts from the liver to the small intestine, where they help break down fats.

Developing a tumor in this duct is a grim fate, as it chokes off the path to the intestine, eventually leading to jaundice, malnutrition, and often infection. Such cancers kill more than 4,000 people in the United States each year _ though it is likely even more common than that, as some patients are misdiagnosed with pancreatic cancer, says Michel Kahaleh, a bile-duct expert at the University of Virginia School of Medicine. He is seeking funds for a trial at 15 medical centers, including Jefferson.

Typically the first sign something is wrong is jaundice. By that time the disease is often too far along for surgery, says Loren, director of endoscopic research at Jefferson.

Chemotherapy and radiation can buy some extra time for the patient, but Correa had been through that already and wanted no more of the nausea and other side effects. So she agreed to try light.

In a randomized European study, photodynamic therapy had extended the life of patients with inoperable bile-duct cancer by more than a year, on average - in some cases several years. It worked so well that the trial was stopped early.