"Initially the risks from lung transplantation for cystic fibrosis patients are quite high, but the risk drops over time, and it becomes worth the risk in the long run," said study co-author Roger D. Yusen, MD, MPH, Assistant Professor of Medicine in the Divisions of Pulmonary and Critical Care Medicine and General Medical Sciences at Washington University School of Medicine in St. Louis.
Cystic fibrosis (CF) is the most common lethal genetic disease in Caucasians, but it affects all races and ethnic groups. The disease affects about 30,000 people in the United States. Approximately 1,000 new cases are diagnosed every year. People with CF live an average of 33 years. They develop severe lung disease, with a combination of airway obstruction, infection, and inflammation that accounts for the majority of deaths from the dis¬ease.
CF patients who receive lung transplants to treat their disease must have a double lung transplant in order for the surgery to be effective, said Dr. Yusen. Lung transplants are not common--approximately 1,000 are performed each year in the United States, and only 150 of them, or 15%, are performed on CF patients. "In the United States, lungs are distributed to patients on the waiting list based primarily on their waiting time, whereas the system for patients waiting for heart or liver transplant depends highly on medical urgency," explained Dr. Yusen.
However, a proposal currently being considered prioritizes patients on the waiting list for lung transplantation based on the medical urgency and the probability of survival after transplantation.
Dr. Yusen and colleagues studied all patients with CF who were on the waiting list for lung transplantation at Washington University School of Medicine and Barnes-Jewish Hospital in St. Louis since the program began in 1988. The study included 247 patients, who were followed through 2002. Most were Caucasian, reflecting the CF population as a whole, and the average age at the time of placement on the waiting list was 28. All the patients had severely impaired lung function and severe symptoms when they were placed on the waiting list.
Of the 247 patients in the study, after one year, 84% of patients were alive while waiting for a transplant, and an equal percentage were alive after having a transplant. After two years, 67% of those waiting for a transplant were alive, compared with 76% who had a transplant. After five years, 55% of transplant patients were alive.
Though transplantation had a significant early death risk compared with continued waiting, the risks significantly decreased over time. Within 15 months, the survival benefit from transplantation became apparent. Based on an average survival of 5.7 years after transplant, the researchers determined that lung transplantation improved the life expectancy of patients with CF by almost 4.5 years.
"Next, we hope to see if transplanted patients are not only living longer, but enjoying a better quality of life than those who remain on the waiting list," Dr. Yusen said.