Canadians with cystic fibrosis are living dramatically longer than a generation ago, to the point where CF is now considered a chronic condition, not strictly a pediatric illness.
New research published in Thursday's edition of the European Respiratory Journal based on numbers from Canada's CF registry shows the median age of survival for CF patients has surpassed 50, up from just 32 in 1990. (That means half live into their 50s.)
In that same period, the median age of death rose to 32 from less than 22 years. (Meaning half the people with CF die before their 32nd birthday and half die after that date.)
It is one of the world's highest survival rates.
"Although these numbers help tell a real success story, we have to remember that people with cystic fibrosis still die prematurely," said Anne Stephenson, a respirologist at St. Michael's Hospital in Toronto.
She said several factors contributed to the better outcomes, including an emphasis on nutrition, better treatment of infections and the advent of lung transplants.
"It's not one thing: Care has improved across the board, thanks to what we've learned from research," Dr. Stephenson said.
CF is a genetic disease that principally affects the lungs and the digestive system. It occurs in children who inherit two defective copies of the gene responsible for cystic fibrosis; it affects about one in every 3,600 children.
While there are treatments for the symptoms – enzymes to help with digestion, antibiotics for infections, exercises to clear the lungs, and transplants – there is no cure.
At 60, Grant Serink is one of Canada's older CF patients. When he was born, very little was known about the condition other than that it was terminal.
"They told my parents I wouldn't live past my teens," he said. (In fact, at that time, children with CF had only a 50-50 chance of living past age four.)
"I guess I was robust – or lucky," Mr. Serink said. Still, he had breathing problems; his nickname at school was the Green Gobber because of his constant coughing. He also had chronic digestive problems, requiring bowel surgery.
Mr. Serink nonetheless built a career in engineering and sales, and had a family, milestones once unthinkable for someone with CF.
But in his early 50s, his health deteriorated. He was in and out of hospital and needed supplemental oxygen until 2011, when he had a double lung transplant.
"It was like being born again," Mr. Serink said. "Life is wonderful now, though I still can't climb Kilimanjaro like young people with CF do today."
Globally, the median age of survival with CF is now 33, according to the World Health Organization. A child born with CF today in the United States is projected to live to 54 for men and 58 for women.
Canada has one the most extensive and organized networks of cystic fibrosis clinics in the world, and a long-standing registry of CF patients. About 4,000 patients are cared for in 42 clinics and, because life expectancy is increasing, about 60 per cent are adults.
Dr. Stephenson, who is director of the CF registry, said the data have contributed greatly to improved care.
For example, CF patients used to follow low-fat diets to ease their digestive symptoms and minimize the enzymes they needed to take (about 40 pills per meal).
This resulted in chronic malnutrition until a physician at the Hospital for Sick Children in Toronto decided more food and more pills was better. The registry showed those patients had fewer complications and a longer lifespan, leading to a shift in treatment.
At the same time, new antibiotics and vaccines protected CF patients from infections. Then, in 1988, the first lung transplant was performed on a CF patient.
In recent years, most provinces have introduced newborn screening for cystic fibrosis, which allows cases to be spotted and treated early.
There are also new drugs such as ivacaftor (brand name Kalydeco) that can significantly boost lung function for CF patients with specific genetic mutations, but those advances are not yet reflected in the data.
Dr. Stephenson said much remains to be done because "there are still too many people with cystic fibrosis dying too young."