癌胚抗原对直结肠偶发高代谢灶良恶性判断

The Application Value of Serum CEA in Incidental Focal Hypermetabolic Colorectal Lesions

探讨肿瘤标记物癌胚抗原(CEA)测定对^(18)F-FDG PET/CT发现直结肠FDG局灶性高代谢灶癌变判断的临床价值。回顾性分析56例意外探测到结直肠局灶性高摄取灶病例,同时行血清CEA测定,将肠镜及病理结果作为标准分组。各组血清CEA水平数据汇总后行单因素方差分析及计算血清CEA水平测定的诊断效率。结果表明:56例结肠局灶性高代谢病灶中,结肠镜及病理检查出结肠癌及腺瘤共43例,阳性预测值(PPV)为76.8%;其中直结肠癌26例,腺瘤17例,其余13例(23.2%)为炎性及生理性改变。结肠癌组、腺瘤组及良性病变组(炎性和生理性摄取)的血清CEA水平分别为(15.0±17.1)μg/mL,(2.23±0.96)μg/mL,(2.51±0.90)μg/mL,恶性病变组与腺瘤组及正常组之间具有显著性差异,F=8.277,P=0.001。结肠癌组与癌前病变组及生理及炎性组之间P值分别为0.001和0.001。血清CEA水平探测局灶性浓聚灶结肠癌变的敏感性、特异性和准确率分别为:84.6%、83%和83.9%。说明^(18)F-FDG PET/CT偶然发现结肠局灶性高摄取病灶中癌前病变和恶性病变阳性率很高,血清CEA水平对局灶性直结肠偶发FDG浓聚灶的恶变诊断具有高的诊断价值。

Aims：To discuss the application value of serum carcinoembryonic antigen （CEA） in incidental colonic focal hypermetabolic detected by PET/CT. Materials and Methods： We retrospectively analyzed 56 unexpected colonic focal uptake of 18F-FDG localized by PET/CT, and then quantitatively analyzed the extent of serum CEA. After PET/CT, the etiology of the findings was confirmed histological by surgery or endoscopic. All the data were assessed for statistical significance using one-way ANOVA. Results： Among the 56 patients who underwent colonoscopy, positive malignant or premalignant lesions were noted in 43 patients （76.8%） with the lesions coinciding with the location described in the PET/CT report. Adenomatous polyps were detected in 17 patients, whereas in 26 patients malignant lesions were confirmed adenocarcinoma. The levels of CEA in colorectal carcinoma group were obviously higher than those in premalignant lesions and normal. The difference in mean CEA between the premalignant adenomatous polyps and the malignant lesions was statistically significant （P = 0.02）. Sensitivity,Specificity and Accuracy of CEA to detected malignant lesion from incidental colonic focal FDG uptake are 84.6%, 83% ,and 83.9% respectively.Conclusions： Our study shows that a significant proportion of patients showing an incidental focal FDG uptake will harbor premalignant （adenomatous polyps） or malignant lesions, and further evaluation of CEA is helpful to discriminable the warranted in such cases.