Incidence and risk factors of cancer in individuals with cystic fibrosis in the UK; a case-control study.

• What is the key question? Which are the most common cancers in the UK cystic fibrosis population and what factors are associated with the incidence of all cancers and in particular gastrointestinal malignancies? • What is the bottom line? The types of cancer in people with CF are varied but reflect those found in the general population. Any cancer and particularly GI cancer appear to be peaking at a younger age, while CFRD is confirmed as a risk factor alongside transplantation. • Why read on? This is the largest study conducted in the UK CF population exploring patterns of cancer incidence and factors associated with it. We observed a high incidence of GI cancers, skin and breast cancers compared to other cancer types. Screening for gastrointestinal cancers could benefit patients at higher risk. To assess cancer incidence in the UK cystic fibrosis (CF) population and determine the associated risk factors, we undertook a nested case-control study of patients with CF, registered with the UK CF Registry. Each case with a first reported cancer between 1999 and 2017 was matched with up to 4 controls: by age (±2-years) and year of cancer diagnosis. Conditional logistic regressions were adjusted for sex, lung function (FEV 1 %), CF related diabetes (CFRD), F508del status, transplant status, DIOS, gastro-oesophageal reflux disease, meconium ileus, Pseudomonas aeruginosa infection, pancreatic insufficiency, proton pump inhibitor (PPI) use, IV antibiotic days and BMI. Results : From 12,886 registered patients, 146 (1.1%) cases of malignancy were identified with 14.3% of cases occurring post solid organ transplant. Site of primary cancer was available for 98 patients: 22% were gastro-intestinal in origin (77% lower, 23% upper GI), 13% skin, 13% breast and 11% lymphomas/leukaemia. In univariable analysis, transplantation increased the odds of reporting any cancer by 2.46 times (95%CI: 1.3-4.6). CFRD also increased the odds of reporting any cancer (OR 2.35; CI: 1.37-4.0) and PPI use (OR 2.0; CI 1.28-3.19). In the multivariable models significant associations with CFRD and transplant remained, while PA infection, PPI use and being overweight showed increased, but statistically insignificant risks. The incidence of GI cancer was strongly associated with CFRD (OR=4.04; 1.47-11.1). Conclusions : We observed a high incidence of lower GI cancers in our cohort which was significantly affected by the presence of CFRD. Screening for gastrointestinal cancers could benefit patients at higher risk. [ABSTRACT FROM AUTHOR]