Prognostic significance of histological features and biological parameters in stage I (pT1 and pT2) colorectal adenocarcinoma

Patients with stage I colorectal cancer have a good prognosis, however, a small fraction of them die of local or distant recurrence after curative resection. The aggressive behavior reflects some biological properties of these tumors. In this study, we evaluated the prognostic role of some histopathological and biological parameters in stage I colorectal carcinomas. From the Colorectal Cancer Registry of Modena, we selected two series of patients; the first included all patients who had died of disease progression, the second included patients with a favorable outcome. The histopathological parameters assessed were grade of differentiation, growth pattern at the invasive tumor front, peritumoral lymphocytic infiltration, tumor budding and vascular invasion. The biological variables were proliferative activity (using Ki-67 nuclear antigen), overexpression of p53 protein and altered expression of the mismatch repair proteins (MLH1 and MSH2). The results showed that an infiltrating growth pattern, absent or sparse peritumoral lymphocytic infiltration, the presence of tumor budding and vascular invasion are significantly related to the risk of recurrence. Among the biological parameters, p53 overexpression was significantly correlated with a poor clinical outcome. Our study showed that the histopathologial features are relevant prognostic indicators and might be used as markers for an appropriate treatment strategy in patients with stage I carcinomas.