Previous Cancer and/or Lymphoma in Patients with Refractory IBD - Con: Anti-TNF or Conventional Immunosuppressive Treatment

Abstract

Patients with IBD and prior cancer are at increased risk of developing recurrent or de novo cancer. Depending on the type of malignancy, risk factors include IBD itself, age, environmental factors, genetic susceptibility and exposure to immunosuppressants (IMS), namely thiopurines, methotrexate and anti-TNFα biologics. The procarcinogenic effect of IMS depends on the type of drug and length of exposure. Thiopurines increase the rates of nonmelanoma skin cancer and lymphomas. Methotrexate is less harmful, but data are scarce. Evidence favoring the ‘safety' of anti-TNF monotherapy is weak because most patients have been exposed to combinations of IMS prior to the development of malignancy. Anti-TNFα biologics may promote tumor proliferation and increase the risk of melanomas. Exclusion of these patients from trials with biologics, physician concerns or fear of incident cancers and medicolegal consequences, and patient concerns have led to a paucity of data regarding IMS treatment of patients with a prior malignancy. In the absence of guidelines, IMS should be avoided especially during the first 2 years after commencing cancer therapy. Depending on disease type, location and severity, 5-ASA, antibiotics, enteric nutrition, steroids alone or in combinations, seton placement, and ‘curative' or ‘diverting' surgery may allow for a crucial drug-holiday period before readministration of IMS. Preventive measures include smoking cessation, UV solar protection, annual skin examination and Pap test. If unavoidable, methotrexate should be the drug of first choice followed by anti-TNFα and then thiopurines. Patients should be managed on a case-by-case basis by a multidisciplinary team of experts.