The role of MIB-1 index in the prognosis of resectable pancreatic head cancer

BACKGROUND/AIMS: Cell kinetics are important indicators of the biological behavior of various human tumors. In this study, we evaluated the prognostic values of the proliferative factors including MIB-1 index, DNA ploidy and S-phase fraction, and further determined the independent prognostic factors in pancreatic head cancer after pancreatoduodenectomy. METHODOLOGY: Patients with pancreatic head cancer undergoing pancreatoduodenectomy were included. Cell proliferative parameters including MIB-1 index, DNA ploidy and S-phase fraction measured by flow cytometry were evaluated and compared with the conventional clinicopathologic factors. RESULTS: There were 21 resectable pancreatic head cancers. By univariate analysis MIB-1 index, cell differentiation and lymphovascular invasion were significant prognostic factors. The 5-year survival rate was 22.2% for overall patients and 29.2% for patients with MIB-1 less than or equal to 11%, while it was 0% for MIB-1 index >11%, p=0.011. Tumors without lymphovascular invasion had significantly better prognosis than those with lymphovascular invasion (median survival: 38 vs. 10 months, p=0.009). The median survival was significantly longer for well-differentiated cancers than for moderately and poorly differentiated cancers (44 vs. 11 and 9 months, p=0.038). There was no correlation between the MIB-1 index and the other 2 conventional prognostic factors. After multivariate analysis, only the MIB-1 index emerged as the independent prognostic factor. CONCLUSIONS: MIB-1 index played a significant role in the prognosis of the resectable pancreatic head cancer and could potentially complement the conventional factors in predicting the prognosis and determining the optimal treatment strategy. MIB-1 index was also an important independent prognostic factor.