Immunohistochemical Study and Clinicopathologic Correlation of Cox-2 and Her-2 Expression in Colorectal Carcinoma: A 5-Year Retrospective Study.

BACKGROUND: Colorectal cancer (CRC) is the fourth most common cancer in Nigeria, and it affects mostly persons in their middle age. In a bid to gain some insight into the molecular characteristics of CRC in our environment, we set out to investigate the expression of COX-2 and HER-2 among Nigerian subjects. OBJECTIVES: To evaluate the expression of COX-2 and HER-2 and determine their correlation with clinicopathologic parameters in surgically resected histologically diagnosed cases of colorectal cancer. METHODS: Fifty-three paraffin-embedded tissue blocks of colorectal resections and corresponding patient information were retrieved from the archives of the Anatomic and Molecular Pathology Department of Lagos University Teaching Hospital. A 4-micron slide section was obtained from each specimen and immunohistochemistry for COX-2 and HER-2 expression was performed. RESULTS: Mean age of cases was 53.9years with an almost equal M:F ratio of 1.12:1. Half of the cases were moderately differentiated adenocarcinoma and 17% were high grade tumors. Eighty three percent of the tumours showed positive cytoplasmic COX-2 expression and extremely low membranous HER-2 positivity was observed in 2%. There was no significant correlation between COX-2 expression and age, gender, tumour location, tumour size, depth of invasion or lymph node status. However, COX-2 expression revealed a significant correlation with tumour grade (p= 0.013). CONCLUSION: This study detects a high COX-2 and low HER- 2 expression in colorectal cancer using immunohistochemistry, suggesting a possible role for COX-2 in CRC pathogenesis. This report should trigger further investigations of both markers vis-à-vis the management of CRC in our environment.

CONTEXTE: Le cancer colorectal (CCR) est le quatrième cancer le plus fréquent au Nigeria et il touche surtout les personnes d'âge moyen. Dans le but de mieux comprendre les caractéristiques moléculaires du CCR dans notre environnement, nous avons entrepris d'étudier l'expression de COX-2 et de HER-2 chez les sujets nigérians. OBJECTIFS: Évaluer l'expression de COX-2 et HER-2 et déterminer leur corrélation avec les paramètres clinicopathologiques dans les cas de cancer colorectal diagnostiqués histologiquement et réséqués chirurgicalement. MÉTHODES: Cinquante-trois blocs de tissus inclus en paraffine provenant de résections colorectales et les informations correspondantes sur les patients ont été récupérés dans les archives du département de pathologie anatomique et moléculaire du Lagos University Teaching Hospital. Une section de lame de 4 microns a été obtenue de chaque spécimen et une immunohistochimie pour l'expression de COX-2 et HER-2 a été réalisée. RÉSULTATS: L'âge moyen des cas était de 53,9 ans avec un rapport M:F presque égal de 1,12:1. La moitié des cas étaient des adénocarcinomes modérément différenciés et 17% des tumeurs de haut grade. Quatre-vingt-trois pour cent des tumeurs présentaient une expression cytoplasmique positive de la COX-2 et une positivité HER-2 membranaire extrêmement faible a été observée dans 2 % des cas. Il n'y avait pas de corrélation significative entre l'expression de la COX-2 et l'âge, le sexe, la localisation de la tumeur, la taille de la tumeur, la profondeur de l'invasion ou le statut des ganglions lymphatiques. Cependant, l'expression du COX-2 a révélé une corrélation significative avec le grade de la tumeur (p= 0,013). CONCLUSION: Cette étude détecte une forte expression de COX- 2 et une faible expression de HER-2 dans le cancer colorectal en utilisant l'immunohistochimie, suggérant un rôle possible de COX-2 dans la pathogenèse du CCR. Ce rapport devrait déclencher des investigations plus poussées des deux marqueurs vis-à-vis de la gestion du CRC dans notre environnement.

Immunohistochemical Study and Clinicopathologic Correlation of Cox-2 and Her-2 Expression in Colorectal Carcinoma: A 5-Year Retrospective Study

BACKGROUND: Colorectal cancer (CRC) is the fourth most common cancer in Nigeria, and it affects mostly persons in their middle age. In a bid to gain some insight into the molecular characteristics of CRC in our environment, we set out to investigate the expression of COX-2 and HER-2 among Nigerian subjects. OBJECTIVES: To evaluate the expression of COX-2 and HER2 and determine their correlation with clinicopathologic parameters in surgically resected histologically diagnosed cases of colorectal cancer. METHODS: Fifty-three paraffin-embedded tissue blocks of colorectal resections and corresponding patient information were retrieved from the archives of the Anatomic and Molecular Pathology Department of Lagos University Teaching Hospital.A 4-micron slide section was obtained from each specimen and immunohistochemistry for COX-2 and HER-2 expression was performed. RESULTS: Mean age of cases was 53.9years with an almost equal M:F ratio of 1.12:1. Half of the cases were moderately differentiated adenocarcinoma and 17% were high grade tumors.Eighty three percent of the tumours showed positive cytoplasmic COX-2 expression and extremely low membranous HER-2 positivity was observed in 2%. There was no significant correlation between COX-2 expression and age, gender, tumour location, tumour size, depth of invasion or lymph node status.However, COX-2 expression revealed a significant correlation with tumour grade (p= 0.013). CONCLUSION: This study detects a high COX-2 and low HER2 expression in colorectal cancer using immunohistochemistry,suggesting a possible role for COX-2 in CRC pathogenesis.This report should trigger further investigations of both markers vis-à-vis the management of CRC in our environment. WAJM 2022; 39(11): 1134­1140.