The Relation between Histopathological Features and P53 Expression in Colorectal Adenocarcinoma in Ugandan Patients

Wismayer R, Kiwanuka J, Wabinga H and Odida M

Published on: 2024-05-31

Abstract

Introduction: In Uganda, the Kampala Cancer Registry has reported a steady increase in colorectal cancer (CRC) in the past 20 years, which is still lower compared to developed high-income countries. The topography of colon tumours is also different, with right-sided colon tumours more commonly observed in developed high-income countries compared to developing low-income countries. The p53 gene is frequently mutated in CRC, and an abnormal protein produced results in early detection of the protein by immunohistochemistry. A poor prognosis and reduced survival have been associated with the detection of p53 in malignant cells. The aim of the study was to determine the association of p53 expression with grade, stage, LVI status, histopathological subtype, and the topography of CRC. Methods: During the period 2008–2021, immunohistochemistry was carried out on 51 patients’ paraffin-embedded tissue blocks of CRC. TP53 expression was detected using the indirect immunoperoxidase method, which uses the monoclonal antibody p53, DAKO Agilent USA, Clone DO-7. The grade and histopathological subtypes of CRC were evaluated using the haematoxylin and eosin stain. The demographic data and topography of the tumours were obtained from the clinical patients’ files and the Kampala Cancer Registry. Results: Out of 51 patients’ tissue blocks that were studied, 27 (52.9%) expressed p53 in the nucleus of malignant CRC cells. There were 20 (74.1%) left-sided colon tumours and 7 (25.9%) right-sided colon tumours that expressed p53, and this reached statistical significance (p = 0.0004). The presence of p53 expression was also significantly associated with the presence of Lymphovascular invasion (p = 0.0561) and the classical adenocarcinoma histological subtype (p = 0.0000). There was a negative correlation between CRC grade and p53 expression (r = -0.1189; p = 0.4059) and between CRC stage and p53 expression (r = -0.1702; p = 0.2324). Conclusions: The intensity of p53 expression is not influenced by the stage or grade of CRC. Similar to other parts of the world, p53 expression is more commonly present in left-sided tumours. Therefore, these findings support the theory that right-sided colon tumours have a different pathogenesis than left-sided colon tumours and hence have a different prognosis.