Malignancy risk in individuals with familial adenomatous polyposis receiving biologics and immunomodulators

Clinicians may be hesitant to prescribe biologics or immunomodulators to individuals with familial adenomatous polyposis (FAP) and comorbid inflammatory disease (CID) because of increased cancer risk. Our aim was to compare the risk of malignancy in FAP individuals with inflammatory bowel (IBD) and/or rheumatic disease that received biologics/immunomodulators to those who did not. Individuals with FAP and CID were included in the study. We compared the incidence of cancer between individuals exposed to biologics/immunomodulators compared to unexposed from the date of diagnosis of comorbid disease till last follow up or death. Hazard ratio (HR) for cancer was computed using Cox regression model and compared by exposure status to biologic/immunomodulators. 25 individuals with FAP and a comorbid inflammatory disease were identified including 9 (36%) with IBD and 16 (64%) with rheumatic disease. 14 (56%) were exposed to a biologic and or immunomodulator. Median duration of biologic/immunomodulator exposure was 48 (2-180) months. 3 (21.4%) in the exposed group compared to 1 (9.1%) in the unexposed group developed cancer with a HR for exposure of 1.92 (CI 0.2-18.5, p = 0.57). Median duration of follow up after the diagnosis of inflammatory disease was 10 (5.5-17.0) years in the exposed and 6 (3.0-15.0) years in the unexposed group. In the exposed group, 1 patient developed gastric and 2 developed colon cancer. One unexposed patient developed medullary thyroid cancer. There is a possible trend of more cancers in the group that received biologics/immunomodulators-but given the small number of patients and p-value, there may be no difference at all. This preliminary finding warrants study in a larger cohort.