免疫化學法糞便潛血陽性反應且下消化道內視鏡檢正常之無症狀者其上消化道內視鏡檢異常結果的臨床預測因子研究

Abstract

研究背景：免疫化學法糞便潛血檢測，上消化道內視鏡檢，下消化道內視鏡檢是當今常用於檢測臨床上有無消化道出血的工具。美國癌症學會建議，在進行大腸直腸癌糞便潛血的檢測，一旦發現糞便潛血檢測呈陽性反應時，下消化道內視鏡檢通常是被建議所應實施的進一步檢查工具。但當下消化道內視鏡檢並未發現任何病灶後，目前並無一致性的追蹤流程，是否應進一步安排上消化道內視鏡檢以排除上消化道出血病灶仍無共識。 研究目的：在於能對於無症狀的患者，當免疫化學法糞便潛血檢測呈陽性反應合併正常下消化道內視鏡檢結果下，是否應進一步安排上消化道內視鏡檢作一前瞻性的觀察與分析，希望在這個研究當中針對這種情形下的族群能夠找到臨床上的特殊性以期能歸納出上消化道病灶之預測因子。 研究方法：前瞻性收集來亞東紀念醫院健康管理中心接受健康檢查的無症狀成年個案作一橫斷性的分析。登錄相關的臨床資料及檢驗數據(年齡、性別、幽門螺旋桿菌感染、血紅素值、血小板過低、飲酒、吸煙、藥物史)，合併免疫化學法糞便潛血檢測、上消化道內視鏡檢、下消化道內視鏡檢結果，各別做單變項迴歸分析，以找出上消化道病灶的潛藏預測因子。接著用邏輯迴歸方法做多元迴歸分析，以確認是否有出血性上消化道病灶的獨立相關因子。 研究結果：總共2796位受試者，其中有397位(14.2%)受試者免疫化學法糞便潛血檢測呈陽性，男性有61.5%。而這397位免疫化學法糞便潛血檢測呈陽性受試者中，有233位受試者下消化道鏡檢無任何病灶。這233位受試者中，有46位發現有上消化道異常病灶，包含有1位為血管增生症，另外45位為上消化道潰瘍。多變項邏輯迴歸分析發現年齡、幽門螺旋桿菌感染、低血紅素值、及飲酒是預測上消化道病灶的獨立因子。在包含有年齡、幽門螺旋桿菌感染、較低的血紅素、飲酒的條件下累積的ROC曲線數值達到0.8。幽門螺旋桿菌感染的特異性及陰性預測值分別為75.4%及90.4%。低血紅素值的特異性及陰性預測值分別為90.4%及82.8%。飲酒的特異性及陰性預測值分別為78.1%及83.4%。總觀，含有任一獨立因子之受試者其上消化道內視鏡檢異常結果的敏感度為不含有任一獨立因子之受試者的10倍。 研究結論：年齡超過50歲，或者是本身有幽門螺旋桿菌的感染，或有較低的血紅素數值或有喝酒的情形，一旦發現免疫化學法糞便潛血呈陽性反應合併正常的下消化道鏡檢情形時，進一步接受上消化道鏡檢是必須的。而這類的族群其上消化道的病灶，大多為良性與可治療的消化性潰瘍。

Background: Immunochemical fecal occult blood test (I-FOBT), esophagogastroduodenoscopy (EGD) and colonoscopy are common tools for detecting gastrointestinal (GI) bleeding today. The American Cancer Society recommends fecal occult blood testing for patients at average risk for colorectal cancer. And, colonoscopy is usually the initial diagnostic procedure for all subjects with positive fecal occult blood tests. However, there have been very few studies pertaining to the workup of patients who present with positive I-FOBT and negative colonoscopy. Besides, it is still controversial for EGD in asymptomatic patients with positive fecal occult blood test and no apparent source of colonic bleeding. Objective: The aim of this study was to prospectively evaluate the diagnostic value of a positive I-FOBT for upper GI lesions after a negative colonoscopy in a large cohort of asymptomatic subjects at average risk for colorectal cancer, and to determine which subjects and clinical characteristics associated with the presence of upper GI lesions consistent with blood loss by EGD. Moreover, we tried to find the significant clinical predictors for positive-EGD in those subjects. Design: A cross-sectional analysis of asymptomatic adults who underwent same day EGD, colonoscopy and I-FOBT examinations in our health screening program from August 2007 through July 2009 was performed in one institution. The analysis was based on data generated from personal medical history (consumption of aspirin, clopidogrel, nonsteroidal antiinflammatory drug, smoking, alcohol consumption), hemogram, endoscopy (including EGD and colonoscopy), pathological findings, H. pylori status and I-FOBT of examinees. The clinical and laboratory data were included in the univariate analysis initially to identify potential predictors for upper GI lesions and to calculate crude odds ratios (ORs). Multivariate analysis was performed with logistic regression to identify independent variables potentially associated with the presence of upper GI lesions consistent with blood loss. Results: A total 2796 of 2871 subjects were enrolled in the study with I-FOBT and completed endoscopy. A total of 397 subjects had positive I-FOBT (14.2%), including 61.5% male subjects. The 233 of 397 subjects had negative colonoscopy. Among these 233 negative colonoscopy subjects, 46 subjects had significant upper GI lesions, including 1 angiodysplasia and 45 peptic ulcer diseases. Multivariate logistic regression analysis showed that age, H. pylori infection, low hemoglobin level, and alcohol consumption were independent factors associated with upper GI lesions. The accumulative ROC curve of area, including age, H. pylori infection, low hemoglobin, and alcohol consumption, was 0.8. The specificity and negative predictive value of positive-EGD were 75.4% and 90.4% for H. pylori infection; 90.4% and 82.8% for low hemoglobin level; 78.1% and 83.4% for alcohol consumption. The overall positive-EGD sensitivity of subjects with any one of the independent factors is 10 times than other subjects without any one of the independent factors. Conclusion: EGD was necessary for healthy subjects with age of 50 years or older, or H. pylori infection, or low hemoglobin level, or alcohol consumption after initial positive I-FOBT and negative colonoscopy. Most of the upper GI diseases were benign and treatable peptic ulcers.