Table_2_The Incidence Rate and Risk Factors of Malignancy in Elderly-Onset Inflammatory Bowel Disease: A Chinese Cohort Study From 1998 to 2020.docx

BackgroundPatients suffering from inflammatory bowel disease (IBD) have an increased risk of cancer. However, the risk of malignancy in patients with elderly-onset IBD (≥60 years) remains controversial. Hence, we aimed to identify and compare the dissimilarities in morbidity and related risk factors between patients with elderly-onset and adult-onset (18–59 years) IBD in a Chinese cohort.
MethodsPatients with confirmed IBD, diagnosed at age ≥18 years, between January 1998 and December 2020 at the Peking Union Medical College Hospital were enrolled. The yearly incidence rates (IRs) for cancer were calculated, and the characteristics were analyzed in these patients.
ResultsA total of 1,480 patients suffering from adult-onset IBD and 129 patients suffering from elderly-onset IBD with a median follow-up period of 4.9 years and 4.8 years, respectively, were included. Patients in the elderly-onset IBD group demonstrated an increased overall incidence of cancer than that demonstrated by patients in the adult-onset group (IR 26.9 versus 9.51, respectively, per 1,000 person-years; relative risk [RR], 2.83). Colorectal cancer was the most common malignancy in the two groups, and patients suffering from elderly-onset IBD demonstrated a higher incidence of the malignancy (IR, 7.07 versus 3.34, respectively, per 1,000 person-years; RR, 2.12). Among the extraintestinal cancers, hematological malignancies and urinary tract cancers (including renal and urinary bladder carcinoma) were common in the elderly-onset group (IR, 4.24 and 4.24 per 1,000 person-years, respectively), whereas thyroid cancer was more common in the adult-onset group (IR, 1.36 per 1,000 person-years). Analysis of clinical characteristics revealed that patients with elderly-onset IBD who developed cancer were more likely to have diabetes and urinary lithiasis (p = 0.041 and 0.035, respectively). In addition, patients in the elderly-onset group had a shorter course from IBD to cancer, less exposure to immunosuppressants, less extraintestinal manifestations, and higher cancer-related mortality. Cox proportional risk regression analysis in the elderly-onset IBD group revealed that diabetes was an independent risk factor for the progression to cancer (hazard ratio [HR], 12.53 [2.379–65.994], P = 0.003).
ConclusionThe risk of malignancy in patients suffering from elderly-onset IBD increased significantly as compared with those with adult-onset disease. Therefore, cancer monitoring should be initiated earlier for patients in the elderly-onset group.

背景 炎症性肠病（Inflammatory Bowel Disease, IBD）患者的癌症风险显著升高。然而，老年起病型（≥60岁）炎症性肠病患者的恶性肿瘤风险仍存在争议。因此，本研究旨在明确并对比中国队列中，老年起病型与成人起病型（18~59岁）炎症性肠病患者的癌症发病率及相关危险因素的差异。

方法 纳入1998年1月至2020年12月期间，于北京协和医院（Peking Union Medical College Hospital）确诊为炎症性肠病且发病年龄≥18岁的患者。计算患者的年度癌症发病率（incidence rates, IRs），并对其临床特征进行分析。

结果 本研究共纳入1480例成人起病型炎症性肠病患者，以及129例老年起病型炎症性肠病患者，两组中位随访时间分别为4.9年与4.8年。老年起病组患者的总体癌症发病率显著高于成人起病组（每1000人年分别为26.9与9.51；相对风险（Relative Risk, RR）=2.83）。结直肠癌为两组患者最常见的恶性肿瘤，且老年起病组患者的结直肠癌发病率更高（每1000人年分别为7.07与3.34；RR=2.12）。在肠外恶性肿瘤中，血液系统恶性肿瘤与泌尿系统恶性肿瘤（包括肾癌与膀胱癌）在老年起病组更为常见（每1000人年分别为4.24与4.24），而甲状腺癌在成人起病组更为多见（每1000人年为1.36）。临床特征分析显示，罹患癌症的老年起病型炎症性肠病患者更常合并糖尿病与尿路结石（分别对应P=0.041与0.035）。此外，老年起病组患者从确诊炎症性肠病至发生癌症的病程更短，免疫抑制剂暴露率更低，肠外表现更少，且癌症相关死亡率更高。针对老年起病型炎症性肠病患者的Cox比例风险回归分析显示，糖尿病是进展为癌症的独立危险因素（风险比（Hazard Ratio, HR）=12.53 [95%置信区间：2.379~65.994]，P=0.003）。

结论 与成人起病型炎症性肠病患者相比，老年起病型炎症性肠病患者的恶性肿瘤风险显著升高。因此，老年起病组患者应更早启动癌症监测。