Jaskiewicz K, Lancaster E, Banach L, Karmolinski A
Department of Pathology, University of Gdansk Medical School, Poland.
Anticancer Res. 1998 Nov-Dec;18(6B):4641-4.
Europeans have a high incidence of colorectal cancer in comparison to Africans. Lack of detectable sequence adenoma-colorectal carcinoma in Africans may suggest the development of adenocarcinoma is de novo. The aim of this study is to assess colonic mucosal proliferative activity in various pathological conditions of diverse population groups. Materials included routinely processed tissue specimens from consecutively resected well- and moderately differentiated colorectal adenocarcinomas from 32 rural Africans (South Africa) and 27 urban Europeans (Poland) and from apparently normal rectal mucous membrane from the age and sex matched each population group (28 and 25 samples respectively). In addition, 32 resected adenomatous polyps were examined in Europeans as well. The MIB 1 monoclonal antibody was used to assay the expression of Ki67 antigen in routinely processed tissue specimens. Proliferative activity in colonic carcinomas was scored by the percentage of positively stained cells. Labelling indices were estimated in 5 crypt compartments in apparently normal colonic mucosa adjacent and distant to the tumour, in mucosal samples of controls from both population groups and in adenomatous polyps from Europeans. The mean age of African patients with adenocarcinoma was markedly lower than in European counterparts (48.6 yrs vs. 66.4 yrs). The overall proliferative activity in cancerous tumours of Africans was higher than in Europeans. The labelling indices were lower in all compartments in normal colonic mucosa in Africans. Overall increase of the labelling indices in adjacent and distant to the tumour mucosa noted when compared to the mucosa of healthy individuals. No such differences were detected between indices in the mucosa adjacent and the mucosa distant to the tumour. Proliferative activity in the mucosa adjacent to adenoma was also higher than in normal mucosa from healthy individuals. Adenomas with marked dysplasia showed higher and diffuse proliferative activity, when regular adenomas shown superficial labelling only. Relatively young age, lack of detectable evidence of adenoma-carcinoma sequence and low proliferative activity in all compartments of mucosa from healthy individuals indicate different etiopathogenesis of colorectal carcinoma in rural Africans.
与非洲人相比，欧洲人的结直肠癌发病率较高。非洲人缺乏可检测到的序列性腺瘤 - 结直肠癌，这可能表明腺癌是从头发生的。本研究的目的是评估不同人群组在各种病理条件下的结肠黏膜增殖活性。材料包括来自32名非洲农村居民（南非）和27名欧洲城市居民（波兰）连续切除的高分化和中分化结直肠癌的常规处理组织标本，以及来自与各人群组年龄和性别匹配的明显正常直肠黏膜的标本（分别为28和25个样本）。此外，还对欧洲人的32个切除的腺瘤性息肉进行了检查。使用MIB 1单克隆抗体检测常规处理组织标本中Ki67抗原的表达。通过阳性染色细胞的百分比对结肠癌的增殖活性进行评分。在肿瘤相邻和远处的明显正常结肠黏膜的5个隐窝区室、来自两个人群组的对照黏膜样本以及欧洲人的腺瘤性息肉中估计标记指数。非洲腺癌患者的平均年龄明显低于欧洲患者（48.6岁对66.4岁）。非洲癌性肿瘤的总体增殖活性高于欧洲人。非洲人正常结肠黏膜所有区室的标记指数较低。与健康个体的黏膜相比，肿瘤相邻和远处黏膜的标记指数总体增加。肿瘤相邻黏膜和远处黏膜的指数之间未检测到此类差异。腺瘤相邻黏膜的增殖活性也高于健康个体的正常黏膜。具有明显发育异常的腺瘤显示出更高且弥漫的增殖活性，而普通腺瘤仅显示表面标记。相对年轻的年龄、缺乏腺瘤 - 癌序列的可检测证据以及健康个体黏膜所有区室的低增殖活性表明非洲农村居民结直肠癌的病因发病机制不同。
