P53 and DCC immunohistochemistry in curative rectal cancer surgery

Background and aims: In rectal cancer altered expression of p53 or DCC may be indicative of poor patient prognosis. This study determined by immunohistochemistry the tumour status of p53 protein and DCC protein in patients with rectal cancer who had a curative resection and were followed-up prospectively and examined the correlation to clinical and pathology variables. Patients and methods: The study included 171 who had a curative resection for rectal cancer: 88 at Concord Hospital (CH) followed up for a mean of 11 years and 83 at Royal Prince Alfred Hospital (RPAH) followed up prospectively for a mean of 4.3 years. Specimens were assessed by immunohistochemical assay of p53 expression (n=170) and of DCC expression (n=168). Results: p53 over-expression was demonstrated in 58% of CH tumours and 59% of RPAH tumours. Absence of normal DCC expression was demonstrated in 66% of CH tumours and 52% of RPAH tumours. On both separate and combined analysis of these groups there were no significant associations by univariate analysis between p53 expression or DCC expression or combinations of p53 and DCC expression and the pathology variables: extent of penetration through bowel wall, lymph node involvement, presence of venous invasion, and tumour differentiation. Conclusion: The immunohistochemical p53 and DCC status of rectal tumours was not associated with other clinical or pathology variables, nor predictive of outcome.