• 10/19/2004
  • Mt. Vernon
  • Beth Durbin
  • Mount Vernon News

Photodynamic therapy, which uses a red laser and a light-sensitive drug to destroy cancer cells without harming normal tissue, is a promising new treatment option for patients with lung and esophageal cancers, according to Dr. Patrick Ross, associate professor of surgery and director of thoracic surgery at the Arthur G. James Cancer Hospital at The Ohio State University in Columbus.

One of his patients, Ray McCann of Mount Vernon suffers from high-grade Barrett’s esophagus disease which is often a precursor to esophageal cancer. The National Digestive Diseases Information Clearinghouse describes Barrett’s as a condition that develops in some people who have chronic gastroesophageal reflux disease (GERD) or inflammation of the esophagus. In Barrett’s esophagus, the normal cells that line the esophagus, called squamous cells, turn into a type of cell not usually found in humans, called specialized columnar cells. Damage to the lining of the esophagus — for example, by acid reflux from GERD —causes these abnormal changes. McCann’s doctor told him the condition is caused in part by smoking, being overweight and the American lifestyle. About 5 to 10 percent of people with Barrett’s develop cancer of the esophagus. Because of the cancer risk, people with Barrett’s esophagus are screened for esophageal cancer regularly. McCann has been undergoing PDT as a precautionary treatment for the past six weeks.

Ross and his team at the James Cancer Hospital have been using this minimally invasive laser light therapy for five years. “We’ve become the busiest center in the northeastern United States when it comes to this method of cancer treatments. Patients under our care have been experiencing a 70 to 80 percent success rate for treatment of high-grade displasion of the lung and esophagus,” said Ross.

Before patients receive the therapy, they are given an intravenous injection of a light-sensitive drug called Photofrin which passes through normal cells but collects in cancerous and precancerous cells. Two or three days after the injection, doctors expose those areas to a red laser, causing a chemical reaction that destroys the diseased cells.

Other lasers kill cancer cells with heat — vaporizing or cutting out tumors, along with a portion of the surrounding healthy tissue. In photodynamic therapy, the red laser’s concentrated beam of light activates the Photofrin to produce a toxic form of oxygen that kills the cancer cells without harming the adjacent tissue.

The procedure is performed in the operating room while patients are under anesthesia. In the procedure, Ross uses a device called a laryngoscope to get a clear view of the patient’s throat and larynx. He then threads a thin fiber-optic conduit through the scope to deliver the laser beam directly to the cancer or premalignant growth. Patients can usually go home the same day following treatment.

Patients may experience some soreness or redness in the area that was exposed to the light, but the major side effect is sensitivity to direct sunlight. The photoactive drug lingers in the cells of the skin and eyes, and those who have been treated must stay out of the sun for about six weeks.

“While I was in the James, any time I left my dimly lit room, I was totally covered with sheets and wearing a hat, gloves and sunglasses. They even wrapped the sheet over my hat. This was really some sight. But it is a minor inconvenience compared to the great benefits of photodynamic therapy,” said McCann.

McCann says he often received strange looks and stares when he was in public places like banks and restaurants and covered up with long sleeves, hat, gloves and dark glasses. He said he always made a point of removing his hat when the circumstance called for common courtesy and readily explained his condition though few people seemed to know about photodynamic therapy.

Other standard treatments for throat and oral cancer, such as surgery and radiation, carry more risks and can have more serious and longer-lasting side effects. For example, six weeks of radiation therapy for throat cancer can cause a drying or stiffening of the vocal cords, reducing voice quality. The tumor can also be replaced by scar tissue, which would also affect the voice.

The U.S. Food and Drug Administration has approved photodynamic therapy to treat esophageal cancer, lung cancer and a precancerous skin condition known as actinic keratosis, but researchers have reported encouraging results in treating other cancers as well. In clinical studies of more than 350 people with early-stage cancers of the mouth, throat and larynx, 88 percent of the patients showed no evidence of the disease after the first treatment.