直肠黏膜渗液游离亚铁血红素检测在结直肠癌早期诊断中的应用价值

Application value of detection of free heme in rectal mucosal secretions for early diagnosis of colorectal cancer

背景与目的:近年来,游离亚铁血红素(FH)检测在恶性肿瘤筛查中表现出较好的筛查效果,然而,目前针对结直肠癌FH检测的研究较少,且样本量小,代表性较差。因此,本研究以较大的样本量进一步评价直肠黏膜渗液FH检测在结直肠癌早期诊断中的应用价值。方法:为分析FH检测对结直肠癌早期诊断的效能以及其普适性或特殊性,将2019年4月—2020年8月于中南大学湘雅三医院胃肠外科行直肠黏膜渗液FH检测的所有符合纳入标准疑似胃肠恶性肿瘤的住院患者均纳入研究,收集患者各项临床资料。将患者区分为胃肠组(所有疑似胃癌与结直肠癌患者)、结直肠组(疑似结直肠癌患者)、右半结肠组(疑似右半结肠癌患者)、左半结肠组(疑似左半结肠癌患者)、直肠组(疑似直肠癌患者),比较FH检测以及粪便隐血试验(FOBT)、癌胚抗原(CEA)、糖抗原19-9(CA19-9)单独或与FH联合检测对各组患者的诊断价值。结果:共将345例患者纳入研究,其中疑似结直肠癌291例,疑似胃癌54例。FH检测结果显示,除右半结肠组外,FH检测的阳性率在胃肠组、结直肠组、左半结肠组、直肠组的恶性肿瘤中均高于同组的良性疾病(均P<0.05)。以病检结果为金标准,FH检测对胃肠癌、结直肠癌、右半结肠癌、左半结肠癌、直肠癌诊断的敏感度分别为40.72%、47.49%、17.39%、57.89%、72.29%,差异有统计学意义(P<0.05);特异度分别为80.65%、78.57%、84.62%、73.33%、71.74%,差异无统计学意义(P>0.05)。排除右半结肠组后,FOBT、CEA、CA19-9单独检测的阳性率在胃肠组、结直肠组、左半结肠组、直肠组的恶性肿瘤中均高于各自组的良性疾病(均P<0.05),但它们的敏感度与特异度在各组间差异均无统计学意义(均P>0.05)。各种不同的联合检测中,结合敏感度与经济性考虑,FH+FOBT为最佳联合检测,其对胃肠癌、结直肠癌、左半结肠癌、直肠癌诊断的敏感度分别为74.86%、85.42%、92.45%、97.22%,特异度分别为64.91%、57.78%、57.14%、60.00%。结论:FH的检测结果具有肿瘤发生位置的特异度,可用于左半结肠癌,尤其是直肠癌的早期诊断,而对胃癌于右半结肠癌的价值不大。FH联合FOBT检测具有经济、简易、高敏感度等优点,为较好的结直肠癌早期诊断方法。

Background and aims:In recent years,free heme(FH)detection has shown good screening performance in malignant tumor screening.However,currently there is limited research on FH detection for colorectal cancer,and the sample sizes are small,with poor representativeness.Therefore,this study was conducted to further evaluate the application value of FH detection in the early diagnosis of colorectal cancer with a relatively large sample size.Methods:To analyze the efficacy of FH detection for early diagnosis of colorectal cancer as well as its universality or specificity,all hospitalized patients suspicious for gastrointestinal malignancy who underwent FH detection in rectal mucosal secretions from April 2019 to August 2020 in the Department of Gastrointestinal Surgery at the Third Xiangya Hospital of Central South University and met the inclusion criteria were included in the study.Clinical data of the patients were collected.The patients were classified into five groups:the gastrointestinal group(all patients suspicious for gastric or colorectal cancer),the colorectal group(all patients suspicious for colorectal cancer),the right colon group(patients suspicious for right-sided colon cancer),the left colon group(patients suspicious leftsided colon cancer),and the rectum group(patients suspicious rectal cancer).The diagnostic value of FH detection as well as fecal occult blood test(FOBT),carcinoembryonic antigen(CEA),and carbohydrate antigen 19-9(CA19-9)alone or in combination with FH detection were compared among the groups of patients.Results:A total of 345 patients were included in the study,among whom there were 291 cases suspicious for colorectal cancer and 54 cases suspicious for gastric cancer.The results of FH detection showed that,except for the right colon group,the positive rate of FH detection in malignant tumors of the gastrointestinal group,colorectal group,left colon group,and rectum group was higher than that of benign diseases in the same group(all P<0.05).Using pathological results as the gold standard,the sensitivity of FH detection for diagnosing gastric cancer,colorectal cancer,right colon cancer,left colon cancer,and rectal cancer was 40.72%,47.49%,17.39%,57.89%,and 72.29%,respectively,and the difference was statistically significant(P<0.05);the specificity was 80.65%,78.57%,84.62%,73.33%,and 71.74%,respectively,and the difference was not statistically significant(P>0.05).After excluding the right colon group,the positive rates of FOBT,CEA,and CA19-9 single detection in malignant tumors of the gastrointestinal group,colon group,left colorectal group,and rectum group were higher than those of benign diseases in the respective groups(all P<0.05),but there was no significant difference in sensitivity and specificity among the groups(all P>0.05).Among the various combined tests,FH+FOBT was the best combined test considering both sensitivity and cost-effectiveness.The sensitivity of FH+FOBT for diagnosing gastric cancer,colorectal cancer,left colon cancer,and rectal cancer was 74.86%,85.42%,92.45%,and 97.22%,respectively,and the specificity was 64.91%,57.78%,57.14%,and 60.00%,respectively.Conclusion:The detection results of FH have specificity for the location of tumor development and can be used for early diagnosis of left-sided colon cancer,especially rectal cancer,but have limited value for gastric cancer and right-sided colon cancer.The combination of FH and FOBT detection has advantages such as economy,simplicity,and high sensitivity,and is a better method for early diagnosis of colorectal cancer.