title: Expression of epidermal growth factor receptor in primary colorectal adenocarcinoma predicts expression in recurrent disease.
abstract: We tested the usefulness of epidermal growth factor receptor (EGFR) immunostaining in primary colorectal adenocarcinoma as a predictor for EGFR status of tumor recurrences in 33 primary tumors and distant recurrences (July 1994 to June 2005). Representative primary and recurrent tumor sections were stained using mouse anti-EGFR antibodies, and only membranous staining of malignant cells was recorded. Results were reported as negative (no staining), 1+ (positivity in <50% of cells), or 2+ (positivity in >50% of cells). Of 33 cases, 19 (58%) showed the same extent of immunopositivity in primary and recurrent tumors. Bivariate logistic regression analysis of primary tumors with 2+ vs those with negative or 1+ staining showed that the primary tumor status had a major predictive relationship with that of recurrence (odds ratio, of 45.99; confidence limit, 4.0-524.9; P = .0021). The difference between the median time to recurrence of primary tumors with the various degrees of staining was not statistically significant. Our reporting method provides a useful correlation between the staining profiles of primary colorectal adenocarcinoma and recurrent disease. It is exceptionally reliable in predicting immunopositivity of a recurrence when more than 50% of cells of the primary tumor are immunoreactive.
authors.affiliation: Department of Pathology, Sunnybrook and Women's College Health Sciences Center, Toronto, ON, Canada.
authors.forename: Mahmoud A
authors.initials: MA
authors.lastname: Khalifa
authors.forename: Corwyn H
authors.initials: CH
authors.lastname: Rowsell
authors.forename: Rebecca A
authors.initials: RA
authors.lastname: Gladdy
authors.forename: Yoo-Joung
authors.initials: YJ
authors.lastname: Ko
authors.forename: Sherif
authors.initials: S
authors.lastname: Hanna
authors.forename: Andy
authors.initials: A
authors.lastname: Smith
authors.forename: Calvin
authors.initials: C
authors.lastname: Law
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000737:chemistry*; D066246:ErbB Receptors / Q000032:analysis*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000737:chemistry*; D013997:Time Factors
chemical_list: D066246:ErbB Receptors