Ki-67 PI (ki-67 + pi)

Distribution by Scientific Domains

Selected Abstracts

Low Ki-67 proliferation index is an indicator of poor prognosis in gastric cancer

Hee Eun Lee MD
Abstract Background and Objectives We designed this study to assess the biologic significance of Ki-67 proliferation index (PI) in gastric cancer. Methods Gastric cancer tissue from 245 patients were immunostained for Ki-67. Ki-67 PI was defined as the percentage of tumor cells positive for Ki-67. In addition, we have previously evaluated the expressions of nine epithelial mesenchymal transition (EMT)-related proteins. The relationship between Ki-67 PI and clinicopathologic parameters, patient survival, and EMT data were sought. Results Low Ki-67 PI was correlated with poorly differentiated histology (P,=,0.034), an advanced T stage (P,<,0.001), and lymph node metastasis (P,=,0.011). Also, the low PI group was found to have a significantly worse prognosis than the high PI group (P,=,0.003, log-rank test). Multivariate analysis revealed that Ki-67 PI remained as an independent prognostic factor (hazard ratio (95% CI),=,0.670 (0.450,0.999)). Furthermore, greater expressional changes of EMT-related proteins were found to be significantly associated with low Ki-67 PI (P,=,0.025). Conclusions These findings suggest that Ki-67 PI is an effective tool for predicting survival in gastric cancer. In addition, we found that an invasive property presented as EMT-related protein expressional changes was inversely correlated with a proliferative activity in gastric cancer. J. Surg. Oncol. 2010;102:201,206. 2010 Wiley-Liss, Inc. [source]

Role and prognostic significance of the Ki-67 index in non-Hodgkin's lymphoma,

Adi Broyde
Expression of Ki-67, a nuclear antigen protein present in all cycling cells, is used to determine the growth fraction of tumors. The aim of this study was to evaluate the role and prognostic significance of the Ki-67 proliferation index (PI) in non-Hodgkin's lymphoma. Ki-67 was assayed immunohistochemically in tissue samples of 319 patients with newly-diagnosed non-Hodgkin's lymphoma. In 268 patients, the Ki-67 PI was correlated with clinical course and outcome. The mean Ki-67 PI ranged from 26.6% in indolent lymphomas to 97.6% in very aggressive lymphomas (P < 0.001). The index was <45% in 82.8% of indolent lymphomas and >45% in 85% of aggressive lymphomas (AUC = 0.877, P < 0.001). In patients with diffuse large B-cell lymphoma (n = 141), a Ki-67 PI of 70% was found to significantly discriminate patients with good or bad prognosis (AUC = 0.65, P = 0.004). Three-year survival was 75% 5.6% in patients with a low Ki-67 index compared with 55.9% 6% in patients with a high index (P = 0.015). In patients with a low IPI (,2), 3-year survival was 94% 4% in those with a Ki-67 index ,70% and 64% 8.1% in those with a higher index (P = 0.002); in patients with bulky disease (>10 cm), the corresponding 3-year survival by Ki-67 index was 100% and 25% 12% (P = 0.012). Our results suggest that the mean Ki-67 PI differs by type of lymphoma. A cut-off value of 45% can help differentiate indolent from aggressive disease. In diffuse large B-cell lymphoma, a cut-off value of 70% can distinguish patients with a good and bad prognosis when combined with other prognostic factors of low IPI score and bulky disease. Am. J. Hematol. 2009. 2009 Wiley-Liss, Inc. [source]