Lung transplants, which have been seen as a treatment of last resort for cystic fibrosis, seem to be rarely beneficial to children with that condition or even worse, they can be harmful, according to a study released on Thursday.

CF is a hereditary disease that affects mainly the lungs and digestive system. The disease leads to progressive disability and in some cases, early death. The disease affects 1 in 3,900 children in the U.S. Europeans and Ashkenazi Jews seem to have higher rates, while 1 in 20 people of Europe descent carry on CF gene.

The study lead by the University of Utah researchers looked through the entire U.S. pediatric experience with lung transplantation for CF between 1992 and 2002. A report of the study was published in November 22 issue of The New England Journal of Medicine.

There were 514 patients under 18 participating at the study, according to the report. A number of 248 children, suffering from CF, who were on the waiting list during the 10-year-period, underwent lung transplantation.

"Children undergoing lung transplant did much worse than expected," Dr. Theodore G. Liou of the University of Utah, Salt Lake City, told Reuters.

Only five children had a significant estimated benefit following the lung transplantation. More than a half – 315 children or 61 percent – encountered risk factors from lung transplant, while 194 children did not have either harmful or beneficial results after the surgery.

"We fully expected, at the start of the study, that we would find a group that did well and others that did not do so well. Unfortunately, we found that the group that most likely did well with transplant was very small, while the group that most likely did poorly (worse than if not transplanted) was quite large," Liou said.

“Although transplantation may improve quality of life, it may not improve survival,” says Dr. Julian Allen of Children’s Hospital of Philadelphia who called the findings “startling” in an editorial in the same journal. He also said that the rules for actual performance of a transplant had also changed.

Until 2005, children underwent lung transplant in the order they were placed on the awaiting list and as soon as the receiving organs were available. Now, the rules have changed. Doctors look mostly at the patient’s condition and sicker children are getting the surgery sooner, Allen said.

"In some cases, children who were put on intensive therapy were deferred, because they got better. There was something about the children in that group who didn't get transplanted that made them get better," Allen said.

This study was intended to deliver new information for patients and their families in order to make better decisions about the timing of lung transplants as Preston Campbell, executive vice president for medical affairs of the Cystic Fibrosis Foundation, which helped fund the study, said.

“Ultimately, I think we will reach a point that children won't require lung transplants" because of advances in care of C.F. patients, he added.