Stapley Sally A, Rubin Greg P, Alsina Deborah, Shephard Elizabeth A, Rutter Matthew D, Hamilton William T
University of Exeter Medical School, Exeter.
School of Medicine, Pharmacy and Health, Durham University, Wolfson Research Institute, Stockton on Tees.
Br J Gen Pract. 2017 May;67(658):e336-e344. doi: 10.3399/bjgp17X690425. Epub 2017 Mar 27.
Incidences of colorectal cancer (CRC) and inflammatory bowel disease (IBD) are increasing in those aged <50 years.
To identify and quantify clinical features in primary care of CRC/IBD in those aged <50 years. This study considered the two conditions together and aimed to determine which younger patients, presenting in primary care with symptoms, would benefit from investigation for potentially serious colorectal disease.
Matched case-control study using primary care records from the Clinical Practice Research Datalink, UK.
Incident cases (aged <50 years) of CRC ( = 1661) and IBD ( = 9578) diagnosed between 2000 and 2013 were each matched with up to three controls ( = 3979 CRC; = 22 947 IBD). Odds ratios (OR) and positive predictive values (PPV) were estimated for features of CRC/IBD in the year before diagnosis.
Ten features were independently associated with CRC/IBD (all <0.001): rectal bleeding, change in bowel habit, diarrhoea, raised inflammatory markers, thrombocytosis, abdominal pain, low mean cell volume (MCV), low haemoglobin, raised white cell count, and raised hepatic enzymes. PPVs were >3% for rectal bleeding with diarrhoea, thrombocytosis, low MCV, low haemoglobin or raised inflammatory markers; for change in bowel habit with low MCV, thrombocytosis or low haemoglobin; and for diarrhoea with thrombocytosis.
This study quantified the risk of serious bowel disease in symptomatic patients aged <50 years in primary care. Rectal bleeding and change in bowel habit are strongly predictive of CRC/IBD when combined with abnormal haematology. The present findings help prioritise patients for colonoscopy where the diagnosis is not immediately apparent.
50岁以下人群中结直肠癌（CRC）和炎症性肠病（IBD）的发病率正在上升。
识别并量化50岁以下人群中CRC/IBD初级保健的临床特征。本研究综合考虑这两种疾病，旨在确定哪些在初级保健中出现症状的年轻患者将受益于对潜在严重结直肠疾病的检查。
使用来自英国临床实践研究数据链的初级保健记录进行匹配病例对照研究。
2000年至2013年期间诊断的年龄小于50岁的CRC（n = 1661）和IBD（n = 9578）的发病病例分别与多达三个对照进行匹配（n = 3979 CRC；n = 22947 IBD）。估计诊断前一年CRC/IBD特征的比值比（OR）和阳性预测值（PPV）。
10个特征与CRC/IBD独立相关（均P < 0.001）：直肠出血、排便习惯改变、腹泻、炎症标志物升高、血小板增多、腹痛、平均红细胞体积（MCV）降低、血红蛋白降低、白细胞计数升高和肝酶升高。腹泻伴直肠出血、血小板增多、MCV降低、血红蛋白降低或炎症标志物升高；排便习惯改变伴MCV降低、血小板增多或血红蛋白降低；腹泻伴血小板增多的PPV均>3%。
本研究量化了初级保健中50岁以下有症状患者患严重肠道疾病的风险。直肠出血和排便习惯改变与血液学异常相结合时，强烈预示CRC/IBD。本研究结果有助于在诊断不明确时对患者进行结肠镜检查的优先排序。
