Patients with cystic fibrosis (CF) are at higher-than-average risk of developing gastrointestinal cancers, especially those who underwent a lung transplant, a new study shows.
Transplant patients with CF were found in this retrospective study to have a five-times greater risk of gastrointestinal cancer than those who have not had a transplant, the researchers found, emphasizing a need for careful screening for small intestine and colon cancers particularly, but also for biliary tract and pancreatic cancers.
The study, “Risk of gastrointestinal cancers in patients with cystic fibrosis: a systematic review and meta-analysis,” was published in the journal The Lancet Oncology.
More effective therapies developed in the last 30 years has significantly improved life expectancy for CF patients, with 70 percent of all patients in developed countries expected to reach adulthood. Treatments now in use range from pancreatic enzymes, to antibiotics targeting the bacteria Pseudomonas (a major cause of CF lung infections), to lung transplant surgeries.
But improvements in life expectancy — prior to 1980, most CF patients died in infancy — has brought an awareness of comorbidities in this population. Reports of cancers in CF patients have also risen since 1980, the study notes.
An international team of researchers conducted a systematic review and meta-analysis of studies published in six different databases — PubMed, Medline, Google Scholar, Scopus, Embase, and Cochrane — to investigate the incidence of CF and gastrointestinal cancers. Additional sources included scientific meetings and studies mentioned in the bibliographies of selected studies.
Their search identified six cohort studies including a total of 99,925 CF patients with a gastrointestinal cancer diagnosis. The studies included those who had undergone a lung transplant and those who had not.
Results showed a significantly higher risk of gastrointestinal cancer in CF patients than in the general population, including site-specific cancers — namely, those of the small intestine, colon, biliary tract (the tubes transporting bile produced by the liver into the small intestine), and the pancreas.
In lung transplant patients, the overall risk a gastrointestinal cancer was five times higher than those without a transplant.
Compared to the public-at-large, all CF patients had a 20 times higher risk of cancer of the small intestine, and 10 times higher for colon cancer.
“Our results support the CF Foundation Task Force recommendation to initiate colon cancer screening at age 40 years, with repeat screening every 5 years thereafter and 3-year surveillance intervals,” the researchers wrote, recommending the small intestine also be examined in the colonoscopy given.
They also proposed a screening strategy for biliary tract and pancreatic cancers with specific imaging techniques, and a blood test for a cancer protein (antigen 19-9) to be performed every two-to-three years for 40-year-old patients who have not had a transplant, and every one-to-two years who those who have.