[A comparative study on the prognostic value of the nuclear expression of protein p53 vis-à-vis histopathology in colorectal cancer].

Objective: To determine the predictive value of p53 nuclear overexpression in comparison with established prognostic pathological features in colorectal adenocarcinoma.
Patients and Methods: 61 patients operated on for cure between January 1989 an December 1991 were included. Expression of p53 protein was examined by immunohistochemistry in paraffin-embedded sections. Tumor localization, depth of bowel wall involvement, lymph nodes metastasis, vascular invasion and PCNA Labelling index were studied in all patients.
Results: Nuclear staining was detected in 27 (44.2%) cases. Positivity was more frequent in tumors with venous invasion and in rectal cancer. p53-positive tumours exhibited a higher likelihood of relapse and lower survival. After adjustment for the other covariates, p53 overexpression was the only factor showing independent prognostic significance on the risk of recurrence. None of the factors analysed evinced independent significant relationship with the risk of death.
Conclusion: Nuclear p53 protein overexpression is closely related to the development of postoperative recurrences and has higher predictive value than standard pathological variables.