Cystic fibrosis and lung transplantation--determination of the survival benefit

Cystic fibrosis is a well acknowledged indication for lung transplantation; however, the optimal timing for transplantation remains debatable. Liou et al. described a score for calculating 5-year probability of survival for patients with cystic fibrosis and concluded that only patients with a probability of survival < 30% gained a survival benefit from transplantation; those between 30% and 50% had equivocal survival effects from transplantation and those > 50% suffered negative effects. The aim of the present study was to determine the validity and applicability of this model.

Data from patients with cystic fibrosis transplanted between January 1995 and July 2001 were retrospectively reviewed. Survival score according to Liou was calculated from data collected before transplantation. Patients were classified according to 5-year probability of survival (group 1: < 30%, group 2: 30%-50%, groups 3-5: > 50%). Actuarial survival rates were calculated separately for each group and compared with the predicted probability of survival.

During the observation period 27 patients were transplanted for cystic fibrosis. Three patients had to be excluded from further analysis because of incomplete pretransplant data. Fifteen patients were classified as group 1 and nine patients as group 2. No patients were eligible for groups 3 to 5. There were nine female patients and six males in group 1, mean age 22.1 +/- 4.9 years. Mean survival time was 918 +/- 787 days; 1-, 3- and 5-year survival rates were 66.6%. Three male patients and six females were classified as group 2, mean age 26.2 +/- 12.2 years. Mean survival time for this group was 701 +/- 617 days, and 1-, 3- and 5-year survival rates were 66.6%.

We found that only patients with a 5-year probability of survival < 50% had been transplanted. For patients in groups 1 and 2 we report identical 5-year survival rates of 66.6%. According to our experience, cystic fibrosis patients with a 5-year probability of survival < 30% and also those between 30% and 50% gain a clear survival benefit from bilateral lung transplantation.