KI-67 LABELING INDEXES IN NONSMALL CELL LUNG-CANCER - COMPARISON BETWEEN IMAGE CYTOMETRY AND FLOW-CYTOMETRY

Expression of the proliferation-associated nuclear antigen Ki-67 was s tudied in 27 human non-small cell lung cancers (NSCLCs), We measured i mmunohistochemical Ki-67 labeling indices using image cytometry (ICM) and flow cytometry (FCM) and compared the indices determined with the two methods, Ki-67 labeling indices of tumor cells ranged from 2% to 5 9% with ICM, and from 3% to 56% with FCM, varying from case to case, T here was a linear correlation of values between the two methods (r = 0 .77, P < 0.05), To examine whether Ki-67 labeling indices represent tu mor proliferative activity, we studied the relationship between the Ki -67 labeling index and the S-phase fraction determined by FCM, There w as a positive correlation between the Ki-67 labeling index and the S-p hase fraction (r = 0.91, P < 0.01), Comparison of Ki-67 labeling indic es and clinicopathological parameters showed lower Ki-67 labeling indi ces in well-differentiated tumors than in moderate and poorly differen tiated tumors (P < 0.05), No correlation was observed between Ki-67 la beling indices and p53 expression, It was concluded that the Ki-67 lab eling index was in fact measured with both ICM and FCM, and that it re presents tumor proliferative activity of NSCLCs. (C) 1997 Wiley-Liss, Inc.