p53 Accumulation in Colorectal Cancer with Hepatic Metastasis

The prevalence of immunoreactive p53 and argyrophilic nucleolar organizer region (AgNOR) numbers were compared between colorectal cancers with (n=44) and without (n=51) hepatic metastasis for at least 5 years. At the same time, the distribution of p53‐positive cells in primary, metastatic, and xenografted tumors from the same individuals were studied. Overall, p53 positivity was found more frequently in the cases with hepatic metastasis than in non‐metastatic controls, regardless of the distribution pattern (P<0.05), whereas AgNOR counts were not different between the two groups. Significant heterogeneity in the distribution of p53 immunoreactivity was noted in both the primary and metastatic lesions. The intratumor distribution patterns of p53 immunoreactive cells in the primary (n=33), metastatic (n=33), and xenografted (n=7) tumors of the same individuals were consistent in the majority of cases. There were a few cases in which the p53 immunoreactive cells were more dominant in the metastatic tumor cells. Our observations suggest that p53 accumulation in colorectal cancer is associated with increased risk for hepatic metastasis, while cell proliferation as represented by AgNOR numbers is not. In addition, heterogeneity of abnormal p53 accumulation in the tumor is maintained during the course of metastasis and even after implantation in nude mouse. p53‐Immunoreactive cells in the population of colorectal cancer cells do not necessarily have higher metastasizing potential.