FDA Approves Use of Light to Kill Tumors

The Food and Drug Administration approved a new therapy Thursday that uses simple light to destroy cancerous throat tumors.

The FDA approved the use of Photofrin to help clear the esophagus when patients’ tumors grow so big that they cannot swallow.

Photofrin is the first of a new type of cancer treatment called photodynamic therapy, in which patients get a drug to make their tumors light-sensitive. The light then kills cancer cells.

“The attractiveness of it is . . . it only makes you sick where the light hits it,” explained FDA drug chief Dr. Robert Temple, who said photodynamic therapy is also being tested against bladder, bronchial and other tumors.

The drawback: Patients remain vulnerable to very severe sunburns for about 30 days, until the drug wears off.

The American Cancer Society estimates that esophageal cancer struck 12,100 Americans in 1995 and killed 10,900 of them, slowly constricting their throats until they could not eat or even swallow their own saliva.

Standard therapy is to chip away at the tumor with a laser, Temple said. But patients whose tumors were too big for the laser to help had nowhere to turn.

Photofrin, manufactured by Canada’s QLT Phototherapeutics Inc., is a chemically modified version of a substance culled from pigs’ blood called porfimer sodium.

Patients are injected with Photofrin. Several hours later, doctors thread fiber-optic cables into the esophagus and shine bright light onto the tumor which starts a process that kills targeted cells.