Non-small cell lung cancer (NSCLC) is one of the most difficult cancers to treat, particularly when it spreads to the lining of the chest cavity. Even if the cancer is operated on, the disease returns in as many as 90 percent of patients. Survival frequently is measured in months. Results with chemotherapy - the current standard of care - are disappointing, with most patients living only between six and nine months.
Joseph Friedberg, M.D., is trying another way. Dr. Friedberg, chief of thoracic surgery at Thomas Jefferson University Hospital and Jefferson's Kimmel Cancer Center, is leading a clinical trial examining the effects of light, or more specifically, photodynamic therapy (PDT), on this type of advanced NSCLC. Such patients have cancer that has "broken out of one lung and seeded the lining of the chest cavity," he explains.
In PDT, a nontoxic photosensitizing agent, photofrin, is injected into the bloodstream and absorbed by cells all over the body. These compounds tend to concentrate more in cancer cells than in normal cells. When the compound is exposed to a certain wavelength of light, it absorbs the light energy and produces a form of oxygen that kills the cells. The damage occurs only where the light is shined.
In the study, each patient is given chemotherapy until the cancer stops responding, meaning the disease begins to grow again. If the cancer has not spread beyond the chest, the patient then receives photofrin 24 hours prior to surgery to remove the tumor. During surgery, he or she receives an appropriate dose of light therapy.