PROCEEDINGS |
The prognostic significance of nuclear accumulation of immuno-histochemically detected p53 in colorectal cancer (CRC) is controversial. In this study we compared, by the Student's t-test, the Area % epithelium: (1) binding lectins (Con A, UEA-1 and PNA following neuraminidase pretreatment); (2) expressing proliferating cell nuclear antigen (PCNA); (3) occupied by nuclei; or (4) reacting with galactose oxidase-Schiff's reagent (GOS) in 86 colorectal specimens that did or did not have nuclear accumulation of p53. Five year survival, tumor recurrence and T-antigen expression were compared to p53 expression by chi square analysis. We found that 79% and 73% of invasive and metastatic CRC specimens, respectively, and 40% of non-neoplastic mucosa and 41% of intraepithelial neoplasms had nuclear accumulation of p53. Neoplasms that expressed p53 were larger than p53 negative neoplasms. When all specimens were considered, p53 expression was not correlated with prognosis or T-antigen expression. However, invasive CRCs that were p53+ and later recurred had more tissue expressing PCNA. The Area % epithelium binding UEA-1 was reduced in metastatic CRCs with p53 expression and poor outcome. GOS reactivity was significantly increased in specimens with nuclear accumulation of p53. Since GOS reactivity may be a dosimeter of exposure to environmental/life style colorectal carcinogens (Carter et al, Validation of GOS, Clin. Can. Res. 3: 1479-89, 1997), this finding suggests that nuclear accumulation of immuohistochemically detected p53 expression in CRCs may reflect environmental factors.