P400 Understanding the impact of TNF-α antagonists on the severity of non-melanoma skin cancer in inflammatory bowel disease and the consequences for therapy

Background

Non-melanoma skin cancer (NMSC) accounts for at least 40% of all new cancer diagnoses in Canada annually and presents a significant cost to the health care system due to the volume of cases. The incidence of NMSC in patients with inflammatory bowel disease (IBD) is higher when compared with the general population. Generally, in a non-IBD population, the risk of further NMSC progression is low; however, little data exists that highlights differences in the clinical course of patients diagnosed with NMSC who have IBD and are TNF-α antagonist exposed. It is unclear if TNF-α antagonist therapy should be discontinued in this patient population.

Our goal is to determine whether TNF-α antagonist exposure in IBD is associated with a high-risk NMSC presentation at diagnosis, as defined by the National Comprehensive Cancer Network (NCCN) stratification. Our secondary objectives include the presence of positive margins following resection, presence of metastatic disease on initial presentation, the requirement of additional therapy to treat NMSC, number of patients who had TNF-α antagonist therapy discontinued following the diagnosis of NMSC and number of individuals with recurrent NMSC.

Methods

Four hundred and twenty-four IBD patients seen at London Health Sciences Centre were reviewed. We have identified 22 patients who were diagnosed with NMSC. Twelve patients had a pre-NMSC TNF-α antagonist exposure while 10 patients who developed an NMSC and had no TNF-α antagonist exposure prior to NMSC diagnosis.

Results

Preliminary results of the primary outcome demonstrate that 50% (6/12) of patients who have been exposed to TNF antagonist therapy presented with a high-risk NMSC lesion at diagnosis compared with 40% (4/10) who were not exposed (OR 5.16, 95% CI 0.47–57.00; p = 0.181). Preliminary results of the secondary outcomes suggest that 25% (3/12) of patients exposed to TNF-α antagonist had positive margins compared with 0% (0/10) of patients who were not exposed. No patients in either group presented with metastatic disease. Twenty-five per cent (3/12) of patients in the exposed group received more advanced treatment compared with 0% (0/10) in the non-exposed group. Eight per cent (1/12) of patients in the TNF-α antagonist group had their IBD therapy changed from a TNF-α antagonist to an alternative biologic class, and 17% of patients (2/12) in the TNF-α antagonist group had recurrent NMSC lesions.