Use of immunosuppressants and biologicals in patients with previous cancer.

Thiopurines promote Epstein-Barr virus-related lymphomas, nonmelanoma skin cancers and acute myeloid leukemias. Anti-tumor necrosis factor (anti-TNF) agents may inhibit or activate carcinogenesis according to the cellular pathways that are activated. A mild increase in the risk of melanoma has been reported in patients exposed to anti-TNF agents. Transplanted patients with previous history of cancer are at high risk of cancer recurrence when receiving posttransplant immunosuppressive therapy, particularly within the first 2 years of treatment. Few data exist for patients with chronic inflammatory disease. In the CESAME cohort that included essentially patients receiving thiopurines, there was no excess incidence of recurrent or new cancer associated with exposure to immunosuppressive therapy in the patients with previous cancer at cohort entry. In clinical practice, the decision to start or resume immunosuppressive therapy in inflammatory bowel disease (IBD) patients with recent cancer should be discussed case by case with cancer specialists. However, taken into account the experience of transplant specialists, it could be suggested not to consider a waiting period for women with adequately treated uterine high-grade cervical dysplasia. For invasive cancers, a waiting period of 2 years should be considered if possible. During this period, treatment of IBD should be restricted to 5-aminosalicylic acid, steroids, nutritional therapy, or surgery, except in case of aggressive IBD that cannot be controlled by these methods. A longer waiting period of 5 years could be recommended for the most aggressive forms of cancers, such as melanomas, aggressive breast cancers, sarcomas, urinary tract cancers, and myelomas.