Rambau Peter F, Odida Michael, Wabinga Henry
Department of Pathology, Bugando University College of Health Sciences, Mwanza Tanzania.
Afr Health Sci. 2008 Dec;8(4):234-8.
It has been shown that colorectal carcinoma is increasing in incidence in African countries. This could be due to change in life style. Molecular pathogenesis of colorectal cancer commonly involves mutation in p53 gene which leads to expression of p53 protein in tumor cells. Expression of p53 protein has been associated with poor clinical outcome and reduced survival in patients.
This was a retrospective laboratory based study carried out in the Department of Pathology Makerere University, Kampala, Uganda. The aim of the study was to evaluate the expression of p53 protein in colorectal carcinoma in Ugandan patients, specifically its association with histological types, degree of differentiation, sites of the tumor and demographic characteristics of the patients.
Immunohistochemistry was carried out on 109 patient's paraffin embedded tissue blocks of colorectal carcinoma diagnosed in the Pathology Department, Faculty of Medicine Makerere University Kampala during the period 1995 to 2005. The indirect immunoperoxidase method using monoclonal antibody p53 DO-7 and Envision (+) Dual link system-HRP to detect p53 expression was used. Haematoxylin and eosin stain was used for evaluation of histological types and degree of differentiation of the tumors. Topography of the tumors and demographic data were obtained from accompanying histological request forms.
Out of 109 patient's tissue blocks that were studied, 61 cases (56%) expressed p53 protein in the nucleus of malignant cells. Right sided colonic tumors were commoner (53.2%) than left sided colonic tumors (46.8%). p53 protein was expressed more in left sided colonic tumors with a significant difference (p<0.05), it was also expressed more in well differentiated tumors and non mucinous adenocarcinomas but with no significant difference (p>0.05). p53 expression was not affected by age or sex.
Frequency of p53 protein expression in Ugandan patients did not differ from that reported in the other parts of the world. It was expressed more in the left sided colonic tumors and this could support the hypothesis that right and left colonic tumors could have different pathogenesis and probably also responsible for difference in prognosis in these two topographic sites.
研究表明，非洲国家结直肠癌的发病率正在上升。这可能是由于生活方式的改变。结直肠癌的分子发病机制通常涉及p53基因的突变，这会导致肿瘤细胞中p53蛋白的表达。p53蛋白的表达与患者不良的临床结局和生存率降低有关。
这是一项基于实验室的回顾性研究，在乌干达坎帕拉马凯雷雷大学病理系开展。该研究的目的是评估乌干达患者结直肠癌中p53蛋白的表达，特别是其与组织学类型、分化程度、肿瘤部位以及患者人口统计学特征的关联。
对1995年至2005年期间在坎帕拉马凯雷雷大学医学院病理科诊断的109例结直肠癌患者的石蜡包埋组织块进行免疫组织化学检测。采用间接免疫过氧化物酶法，使用单克隆抗体p53 DO-7和Envision(+)双链系统-HRP检测p53表达。苏木精和伊红染色用于评估肿瘤的组织学类型和分化程度。肿瘤的部位和人口统计学数据来自随附的组织学申请表。
在研究的109例患者组织块中，61例(56%)在恶性细胞核中表达p53蛋白。右侧结肠肿瘤(53.2%)比左侧结肠肿瘤(46.8%)更常见。p53蛋白在左侧结肠肿瘤中的表达更多，差异有统计学意义(p<0.05)，在高分化肿瘤和非黏液腺癌中的表达也更多，但差异无统计学意义(p>0.05)。p53表达不受年龄或性别的影响。
乌干达患者中p53蛋白表达的频率与世界其他地区报道的频率没有差异。它在左侧结肠肿瘤中的表达更多，这可能支持这样的假设，即左右侧结肠肿瘤可能有不同的发病机制，也可能是这两个部位预后差异的原因。
