COMPARATIVE SCORING BY VISUAL AND IMAGE-ANALYSIS OF CELLS IN HUMAN SOLID TUMORS LABELED FOR PROLIFERATION MARKERS

This study determined the validity of an image analysis program develo ped to score individual cells in human solid tumors labeled by prolife rating cell nuclear antigen (PCNA) or bromodeoxy-uridine (BrdUrd), The program used nuclear size, grey level, and perimeter convexity to ide ntify cells, and evaluated labeling by the fraction of nuclear area di splaying positive immunostaining (MPB). Total cell number (TC) and Brd Urd or PCNA labeling index (LI) were evaluated in 142 images using vis ual (TCvisual, LI(visual)) and image analysis (TCIA, LI(IA)). Without the perimeter convexity criterion, image analysis resulted in a) TCIA equal to TCvisual in spite of the presence of various non-cellular obj ects and b) significant correlations between LI(IA) and LI(visual) for PCNA and BrdUrd, although for these markers the LI(IA) were 4 and 6% lower than their respective LI(visual). Both visual and image analyses yielded significant inter-investigator variation among three investig ators (coefficient of variation between 8.2 and 47.5%) and significant intra-investigator, inter-day variation (coefficients of variation be tween 3.8 and 51.8%). We conclude that image analysis using size, grey level and MPB is a valid alternative to visual scoring of PCNA and Br dUrd ii in individual cells. (C) 1997 Wiley-Liss, Inc.