Cystic Fibrosis Prognosis

By Dr. Catherine Shaffer, Ph.D.Reviewed by Dr. Liji Thomas, MD

Cystic fibrosis is a disease affecting the lungs and many other organs of the body. It causes a thick, sticky mucus to build up which blocks airways and traps bacteria, leading to frequent infections. Other organs affected include the pancreas, intestines, liver, sinuses, and reproductive organs.

Cystic fibrosis patients suffer from difficulty in breathing, persistent cough, wheezing, intolerance to exercise, and nasal inflammation. They also experience digestive symptoms like greasy stools, poor growth in childhood, and severe constipation.

Cystic fibrosis is caused by a defect of the cystic fibrosis transmembrane conductance regulator (CFTR) protein. The severity of symptoms and the prognosis vary depending on the specific genetic defect leading to the disease, as well as the age and other associated health problems of the patient. The current average life expectancy for cystic fibrosis patients in the U.S is about 37 years.

Cystic Fibrosis in Childhood

Children with cystic fibrosis often maintain a good quality of life and are able to attend school and engage in other activities. Young adults with cystic fibrosis often finish school, embark on careers and build families. Female patients have consistently poorer survival rates than males between the ages of 2 and 20 for unknown reasons.

Cystic Fibrosis in Adulthood

Once an exclusively pediatric disease, cystic fibrosis is now a disease of adults due to improved treatments,. Patients engage in daily regimens including airway clearance, inhaled mucoactive agents and antibiotics, and high-calorie, high-fat diets to manage the disease. More advanced drugs are available for treating the disease and its complications. Universal newborn screening has also improved survival by identifying infants with cystic fibrosis as early as possible so that they can begin treatment.

Eighty percent of people born with cystic fibrosis will survive to adulthood. However, lung complications accumulate as patients with cystic fibrosis get older. Comorbid conditions become more common with advancing age. Chronic renal insufficiency, hypertriglyceridemia, and colon cancer are found to occur more commonly in adults with cystic fibrosis than in those without it.

Risk Factors

Analysis of a registry of cystic fibrosis patients maintained by the Cystic Fibrosis Foundation has revealed some risk factors that point to greater mortality in the disease.

Higher risk of death is associated with female gender, non-white race, and symptomatic presentation of the disease (meaning the patient already has respiratory, gastrointestinal, or other symptoms of the disease at the time of diagnosis). Only 7.6 percent of patients are asymptomatic upon diagnosis.

Among patients with genotype information, those who were homozygous for the delF508 mutation had a higher risk of mortality than those who were heterozygous. As well, patients who did not have the delF508 mutation at all also fared worse than patients who were heterozygous for the mutation.

Advances in Life Expectancy

In 1962, the median survival for patients with cystic fibrosis was just 10 years, with a few individuals surviving into their teens. Scientific advances in understanding the causes of cystic fibrosis and discovery of new therapies has changed those numbers radically.

An analysis of survival in cystic fibrosis in 2000 compared to 2010 showed improvement at a rate of 1.8 percent per year. The projected survival of children born and diagnosed with the disease in 2010 was 39 years, if mortality rates continue to improve at the current rate.

References

1. Cystic fibrosis life expectancy, https://cysticfibrosisnewstoday.com/cystic-fibrosis-life-expectancy/
2. Case-mix adjustment for evaluation of mortality in cystic fibrosis, https://www.ncbi.nlm.nih.gov/pubmed/11802245
3. Longevity of Patients with Cystic Fibrosis in 2000 to 2010 and Beyond: Survival Analysis of the Cystic Fibrosis Foundation Patient Registry, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4687404/
4. What is Cystic Fibrosis? https://www.nhlbi.nih.gov/health/health-topics/topics/cf/
5. NIH Genetics Home Reference, Cystic Fibrosis, https://ghr.nlm.nih.gov/condition/cystic-fibrosis
6. Newborn Screening for Cystic Fibrosis, https://www.cdc.gov/mmwr/preview/mmwrhtml/rr5313a1.htm

Further Reading

• All Cystic Fibrosis Content
• Cystic Fibrosis (CF)
• Cystic Fibrosis Causes
• Cystic Fibrosis Symptoms
• Cystic Fibrosis Diagnosis