Comparative study of carcinoembryonic antigen and epithelial membrane antigen expression in normal colon, adenomas and adenocarcinomas of the colon and rectum.
Comparative study of carcinoembryonic antigen and epithelial membrane antigen expression in normal colon, adenomas and adenocarcinomas of the colon and rectum.
复制标题
正常结肠、结肠、直肠腺瘤和腺癌癌胚抗原和上皮膜抗原表达的比较研究。
作者：
B. Davidson;V. Sams;J. Styles;C. Dean;P. Boulos
肿瘤抗原表达的异质性可能需要在单个患者或肿瘤的基础上选择单抗，以便进行适当的肿瘤定位。癌胚抗原(CEA)和上皮膜抗原(EMA)在结直肠癌患者中的表达以前没有进行过比较。应用抗癌胚抗原(CEA)和癌胚抗原(EMA)的单抗，对51例结直肠癌患者的癌组织(n=52例)、癌旁正常结肠(n=45例)、同步腺瘤(n=11例)和结节转移瘤(n=49例)进行了间接免疫过氧化物酶染色。原发灶中阳性细胞百分率依次为1：<25%、2：25~49%、3：50~75%、4>75%。所有原发结直肠癌均表达CEA，其中43例表达EMA(83%)。分级显示CEA大于EMA的有39例，相等的有11例，小于EMA的有2例。高分化癌CEA染色分级为3级或4级的比例(23/27)高于中分化癌(11/22)(p<0.01)。EMA的相应数字为27例中的4例和22例中的3例(无统计学意义)(NS)，尽管大多数(86%)为1级和2级。1级CEA在15例近端病变中6例表达，在37例远端病变中仅2例表达(P<0.01，x~2检验)，而EMA的等值数字为3/15和6/37(NS)。结节均表达CEA，其中45例表达EMA(92%)，45例正常结肠切片中29例表达CEA(%)，腺瘤均表达CEA。EMA在正常结肠和腺瘤中均不表达。这些结果表明，对于结肠癌，EMA的表达比CEA更具特异性，但敏感性较低，而且与肿瘤的分化程度和部位无关。因此，在肿瘤活检的基础上选择抗癌胚抗原或癌胚抗原的单抗可能会改善结直肠癌患者的影像或治疗中的肿瘤定位。
The heterogeneous nature of tumour antigen expression may require selection of monoclonal antibodies on an individual patient or tumour basis to allow adequate tumour localisation. Carcinoembryonic antigen (CEA) and epithelial membrane antigen (EMA) expression has not previously been compared in colorectal cancer patients. Sections of cancer (n = 52), adjacent normal colon (n = 45), synchronous adenomas (n = 11) and nodal metastases (n = 49) were examined by indirect immunoperoxidase staining in 51 consecutive patients with colorectal cancer using monoclonal antibodies to CEA and EMA. The percentage of cells with positive staining in the primary tumours was graded 1: less than 25%, 2: 25-49%, 3: 50-75%, 4 greater than 75%. All primary colorectal cancers expressed CEA and 43 of 52 expressed EMA (83%). Grading showed CEA greater than EMA in 39, equal in 11 and less in two. Well differentiated cancers were more frequently graded three or four for CEA staining (23 of 27) than moderately differentiated cancers (11 of 22) (p less than 0.01). Equivalent figures for EMA were four of 27 and three of 22 (not significant) (NS) although the majority (86%) were graded 1 and 2. Grade 1 CEA expression was found in six of 15 proximal and only two of 37 distal lesions (p less than 0.01, chi 2 test) while for EMA equivalent figures were three of 15 and six of 37 (NS). Nodal deposits all expressed CEA and 45 of 49 expressed EMA (92%); 29 of 45 normal colon sections showed CEA expression (64%) as did all adenomas. EMA was not expressed by normal colon or adenomas. These results suggest that EMA expression is more specific but less sensitive than CEA for colonic cancer and is independent of tumour differentiation and site. Thus selecting monoclonal antibodies to CEA or EMA based on tumour biopsies may allow improved tumour localisation for imaging or therapy in patents with colorectal cancer.