Higher body mass index (BMI) and pancreatic insufficiency could be risk factors for cancer in adults with cystic fibrosis (CF) according to a new study published in Cancer Causes & Control.

“In this large cohort study of adults with CF, increased BMI was associated with a reduced risk of cancer overall in transplanted but not in non-transplanted patients. Additionally, a higher BMI 2 years after transplant was also associated with a reduced risk of cancer,” the authors said. They hypothesized that such an association between BMI and cancer could be explained by a less dysbiotic gut microbiome in patients with CF who had a higher BMI.

Transplanted patients with CF who developed cancer had higher BMIs compared with those who did not. However, multivariable logistic regression analyses showed that underweight, overweight, and obese patients were less likely to have cancer when compared with normal weight patients.

On the other hand, the authors did not find an association between BMI and risk of cancer in nontransplanted patients with CF. Multivariable logistic regression analyses did show an association between overweight BMI class, but not overall BMI class, and reduced cancer risk. Pancreatic insufficiency and higher forced expiratory volume in 1 second were independently associated with an increased risk of cancer.

Moreover, older age was independently associated with an increased risk of cancer in both transplanted and nontransplanted patients with CF.

In contrast, the authors did not find any association between the distribution of CFTR mutation class, sex, or BMI trajectory and risk of cancer.

The study included 26,199 patients from the CF Foundation Patient Registry. Of those, 446 (1.7%) developed cancer, with a higher proportion of cancer cases found among transplanted CF patients compared with nontransplanted patients (3.8% vs 1.4%).

Reference

Knotts RM, Jin Z, Doyle JB, Keating C, DiMango E, Abrams JA. Body mass index and additional risk factors for cancer in adults with cystic fibrosis. Cancer Causes Control. Published online September 30, 2022. doi:10.1007/s10552-022-01635-1