As he begins chemotherapy for lung cancer this week, ABC News anchor Peter Jennings faces sobering odds in beating the disease.
Only 15 percent of Americans with lung cancer survive five years after diagnosis, according to the American Cancer Society.
"There are not many success stories," acknowledged Dr. David Wilson, co-director of the multidisciplinary lung cancer clinic at the University of Pittsburgh Medical Center. Most patients, he said, are incurable by the time they appear for treatment.
Lung cancer is the leading cause of cancer-related death in both men and women. Still, no effective screening test exists to help identify the disease at an early, treatable stage, and clinicians say advances in treatments have been steady, but still modest.
More than 163,000 Americans are expected to die from lung cancer this year. They account for about 29 percent of the nation's cancer deaths.
Patients have the best chance of a cure when the disease is still localized. But only 16 percent of lung cancers are discovered at this early stage, according to the cancer society.
Forty percent of patients already have progressed to the most advanced stage of lung cancer, stage IV, by the time the disease is diagnosed, said Dr. Chandra Belani, co-director of the lung and thoracic cancer program at the University of Pittsburgh Cancer Institute. That stage involves cancer that has spread beyond the chest or is found in multiple lobes of the lung.
Patients often do not notice a problem until the disease has advanced significantly, he said. They typically appear for treatment when they experience fatigue or cough, blood in their sputum, shortness of breath or fever.
Lung cancers can grow a year or more before patients notice, said Dr. Robert Keenan, director of thoracic surgery at Allegheny General Hospital. The disease "is very difficult to diagnose because it remains silent for so long," he said.
Like Belani, Keenan said that news accounts suggest that Jennings has at least stage III cancer, meaning that it has spread to the central lymph nodes.
He probably has non-small cell cancer, which affects about four out of five lung cancer patients, Keenan said.
Small cell cancer is more deadly and tends to occur in patients who smoke or who have recently stopped smoking, he said.
Jennings was a heavy smoker until the 1980s, when he kicked the habit. He resumed smoking after the terrorist attacks in 2001, only to quit again later.
Cigarette smoking is by far the most important risk factor for lung cancer, according to the cancer society.
Surgery is the best option for cancer detected in its early stages, Keenan said. The five-year survival rate for early stage cancers treated by surgery, or a combination or surgery and chemotherapy, is as high as 80 percent to 90 percent.
Keenan said Jennings likely has advanced cancer, based on reports that he has felt ill for several months. The rasp in Jennings' voice when he announced last week that he had cancer could have resulted from the fact that spreading lung cancer can affect nerves associated with the vocal cords, he said.
The five-year survival rate for patients with stage IV cancer is about 5 percent, though it can be as high as 30 percent for patients with stage III cancer, he said.
Efforts to control the side effects of chemotherapy have improved, he said, so Jennings may well be able to fulfill his plans to continue his news anchor duties, though he likely will lose his hair. An advance of the cancer poses a greater obstacle to those plans than side effects from the months-long chemotherapy regimen, he added.
The lack of an effective screening test for lung cancer is a significant problem in battling the disease.
"It's the only major cancer in the world for which there is no efficacious screening technique," Wilson said. "We're all searching eagerly for any type of screening test that could be proved to reduce deaths from lung cancer."
A national study involving 50,000 people is under way to determine whether CT scans could be an effective screening tool, he said. Results are expected in two years.
Another effort, the Pittsburgh Lung Cancer Screening Study, has enrolled 4,000 local residents to assess not only the effectiveness of CT scans, but also blood tests and sputum tests, for screening people at high risk of developing the disease, said Wilson, co-investigator of the study.
One problem, said Wilson, is that CT scans detect nodules in the lungs that may not be cancerous and surgery to remove nodules can be risky. In the Pittsburgh study, he noted, about 40 percent of test subjects have nodules, but only around 1 percent of those patients will develop lung cancer.
Developing methods to determine which nodules are cancerous "is an intense area of research, both here and around the country," he said.
Belani noted that steady progress has been made in chemotherapy treatment.
For patients with advanced lung cancer treated with chemotherapy, median survival rates range from eight to 10 months, up from four to six months in the late 1970s, he said.
Patients treated with chemotherapy and the new drug Avastin have a median survival rate of 12.5 months, he said. Another drug, Tarceva, has improved survival in patients with recurrent lung cancer from 4.5 months to 6.7 months, he said, and a number of other drug treatments are being investigated.
While some patients beat the odds, Keenan called the overall progress in treatment disappointing. "We haven't made the kind of profound impact on survival rates that we'd like to have."
Joe Fahy can be reached at firstname.lastname@example.org or 412-263-1722.