Expression of P53, P27 and KI-67 in colorectal cancer patients of various ethnic origins: Clinical and tissue microarray based analysis

Background: This study was conducted to determine survival according to the expression of molecular markers in colorectal cancer (CRC) patients of various ethnic origins. Methods: Resection of primary tumor was conducted on 171 patients with CRC. Corresponding archived paraffin-embedded blocks were retrieved and tissue microarray (TMA) constructed. Immunohistochemical staining of the TMA for p53, p27 and Ki-67 was quantified by two independent pathologists. Survival was analyzed using the Kaplan-Meier product limit method. Results: With a median follow-up of 65 months, 56 patients (32.7%) died of disease. AJCC stage correlated with disease-free (DFS, P < 0.0001) and overall survival (OS, P < 0.0001). IHC staining was positive for Ki-67 in 77.4%, p53 in 55.8% and p27 in 54.2% of patients. Primary tumor marker expression did not correlate with DFS or OS. The 5-year DFS for Ashkenazi Jews was 75%, significantly higher than Sephardic Jews (SJ) 64% and Palestinian Arabs (PA) 38%, P = 0.001. Conclusions: Ethnicity among Ashkenazi and SJ and PA appears to have a significant impact on disease outcome in patients with CRC patients, while primary tumor expression of p53, p27 and Ki-67 was unrelated to disease outcome.