BACKGROUND: Immunosuppression is a risk factor for carcinogenesis. Thiopurines specifically contribute to this. As thiopurines are used more aggressively in the treatment of IBD, it is likely that we will see more thiopurine-related malignancy. AIM: To review the literature, exploring how immunosuppression, thiopurines specifically, might cause cancer and which malignancies occur in practice, placing specific emphasis on IBD cohorts. METHODS: Search terms included 'malignancy' 'cancer' 'azathioprine' 'mercaptopurine' 'tioguanine (thioguanine)' 'thiopurine' and 'inflammatory bowel disease' 'Crohn's disease' 'ulcerative colitis'. We also searched for specific cancers (lymphoma, colorectal cancer, skin cancer, cervical cancer) and reviewed the reference lists of the articles detected. RESULTS: Immunosuppression is associated with an increased risk of cancer. Thiopurines are associated with specific additional risks. In IBD cohorts, very few thiopurine-related malignancies have been reported. However, studies suggest a relative risk of 4-5 for lymphoma. This still translates into a low actual risk, (one extra lymphoma in every 300-1400 years of thiopurine treatment). CONCLUSIONS: Whilst we must be aware of this risk and counsel our patients appropriately, thiopurines remain a mainstay of IBD therapy. We present practical advice aimed at minimizing our patients' risk of developing malignancy, whilst optimizing the benefits that thiopurines can provide.
BACKGROUND: Immunosuppression is a risk factor for carcinogenesis. Thiopurines specifically contribute to this. As thiopurines are used more aggressively in the treatment of IBD, it is likely that we will see more thiopurine-related malignancy. AIM: To review the literature, exploring how immunosuppression, thiopurines specifically, might cause cancer and which malignancies occur in practice, placing specific emphasis on IBD cohorts. METHODS: Search terms included 'malignancy' 'cancer' 'azathioprine' 'mercaptopurine' 'tioguanine (thioguanine)' 'thiopurine' and 'inflammatory bowel disease' 'Crohn's disease' 'ulcerative colitis'. We also searched for specific cancers (lymphoma, colorectal cancer, skin cancer, cervical cancer) and reviewed the reference lists of the articles detected. RESULTS: Immunosuppression is associated with an increased risk of cancer. Thiopurines are associated with specific additional risks. In IBD cohorts, very few thiopurine-related malignancies have been reported. However, studies suggest a relative risk of 4-5 for lymphoma. This still translates into a low actual risk, (one extra lymphoma in every 300-1400 years of thiopurine treatment). CONCLUSIONS: Whilst we must be aware of this risk and counsel our patients appropriately, thiopurines remain a mainstay of IBD therapy. We present practical advice aimed at minimizing our patients' risk of developing malignancy, whilst optimizing the benefits that thiopurines can provide.
Authors: John K Marshall; Anthony R Otley; Waqqas Afif; Charles N Bernstein; Lawrence Hookey; Grigorios Leontiadis; Remo Panaccione; Brian Bressler Journal: Can J Gastroenterol Hepatol Date: 2014 Jul-Aug
Authors: Heimo H Wenzl; Christian Primas; Gottfried Novacek; Alexander Teml; Anna Öfferlbauer-Ernst; Christoph Högenauer; Harald Vogelsang; Wolfgang Petritsch; Walter Reinisch Journal: Dig Dis Sci Date: 2014-11-08 Impact factor: 3.199
Authors: Neil E McCarthy; Charlotte R Hedin; Theodore J Sanders; Protima Amon; Inva Hoti; Ibrahim Ayada; Vidya Baji; Edward M Giles; Martha Wildemann; Zora Bashir; Kevin Whelan; Ian Sanderson; James O Lindsay; Andrew J Stagg Journal: J Clin Invest Date: 2015-07-13 Impact factor: 14.808