Clinical significance of Ki-67 proliferation index in disease progression and prognosis of patients with resected colorectal carcinoma

Abstract

Background: The prognostic role of proliferation markers in patients with colorectal neoplasia is inconclusive. The aim of this study was to evaluate proliferation markers in patients with colorectal carcinoma, to relate these to standard clinicopathological findings and to investigate their potential role in the prediction of long-term survival. Methods: Archived formalin-fixed, paraffin-embedded tissue samples from a cohort of 106 patients who underwent curative resection for colorectal carcinoma were analysed to determine a Ki-67 (MIB-1)-derived proliferation index (PI) using a double immunostaining technique. The relationship between PI and standard clinicopathological variables was assessed and its association with long-term survival evaluated. Results: A significant association was found between PI and tumour (T) status (P = 0·001), lymph node (N) involvement (P = 0·0098), the presence of distant metastases (P < 0·010) and advanced stage of disease (P < 0·001). On multivariate analysis, PI was shown to be an independent prognostic factor for long-term survival (hazard ratio 2·1 (95 per cent confidence interval 1·1 to 4·1); P = 0·032). Conclusion: Cell proliferation is significantly associated with tumour progression and may be used to identify patients with a predicted adverse outcome after resection of colorectal carcinoma.