Mill J, Lawrance I C
Centre for Inflammatory Bowel Diseases Fremantle Hospital, WA, USA -
Minerva Gastroenterol Dietol. 2013 Sep;59(3):261-72.
Inflammation and immunosuppression are two major risk factors for the development of carcinogenesis in inflammatory bowel disease (IBD). While the natural history of uncontrolled inflammation in the bowel may lead to a higher incidence of colorectal cancer (CRC), surveillance colonoscopy has resulted in earlier detection of dysplasia and cancer, prompting earlier surgical intervention and improved prognosis, while chemoprevention in the form of the anti-inflammatory 5-aminosalicylate acids and immunosuppression could potentially decrease the incidence of CRC. Numerous extra-intestinal cancers such as hepatobiliary and pancreatic malignancies, however, are also noted to be more prevalent in IBD patients particularly with co-existing primary sclerosing cholangitis. Somewhat ironically, however, the medications used to control the inflammation in IBD may also be responsible for the development of other cancers. The increased risk of lymphoma and skin cancers associated with immunosuppressive medication use may potentially be due to loss of immunosurveillance and in the case of lymphoma, the presence of oncogenic viruses (i.e., Epstein-Barr virus). Thus the challenge for both the treating physician and IBD patient is to balance the risk of any potential treatment against patient symptoms and the natural history of uncontrolled inflammation from their disease.
炎症和免疫抑制是炎症性肠病（IBD）发生癌变的两个主要危险因素。虽然肠道内未控制的炎症的自然病程可能导致结直肠癌（CRC）的发病率更高，但监测结肠镜检查已能更早地检测到发育异常和癌症，促使更早进行手术干预并改善预后，而以抗炎5-氨基水杨酸类药物形式进行的化学预防以及免疫抑制可能会降低CRC的发病率。然而，许多肠道外癌症，如肝胆和胰腺恶性肿瘤，在IBD患者中也更常见，尤其是合并原发性硬化性胆管炎的患者。然而，颇具讽刺意味的是，用于控制IBD炎症的药物也可能导致其他癌症的发生。与使用免疫抑制药物相关的淋巴瘤和皮肤癌风险增加，可能是由于免疫监视功能丧失，就淋巴瘤而言，还可能是由于致癌病毒（即爱泼斯坦-巴尔病毒）的存在。因此，对于治疗医生和IBD患者来说，挑战在于平衡任何潜在治疗的风险与患者症状以及疾病未控制炎症的自然病程。
