COLORECTAL-CANCER AND NONCANCER PATIENTS HAVE SIMILAR LABELING INDEXES BY MICROSCOPY AND COMPUTED IMAGE-ANALYSIS

The labeling index (LI), a microscopic measurement of proliferative ac tivity in colonic crypts, is proposed as an indicator of colonic cance r risk. Computed image analysis of proliferative regions is less labor intensive and more objective than is direct microscopy but has not be en validated for labeling indices by direct comparison. The authors co mpared colonic crypt proliferation in 26 cancer and 13 noncancer patie nts by using Ki-67 monoclonal antibody (McAb) labeling of flat mucosa obtained from surgically removed, frozen specimens. In cancer patients , the mucosa specimen was excised 10 cm away from the tumor, and the L I was determined microscopically for the whole crypt, the upper two th irds, and the upper one third of 15 crypts. Nuclear antigen levels of 15 whole crypts were determined by using the CAS-200 computed image an alyzer (Cell Analysis Systems, Elmhurst, IL). Cancer and noncancer spe cimens were compared as were microscopically determined LT and stained nuclei specimens by using image analysis. No statistically significan t difference in proliferative activity of whole crypts, or the upper t wo thirds of crypts, was observed between cancer specimens and noncanc er specimens from using either technique. However, a significant corre lation existed between microscopic analysis and computed image analysi s of labeled nuclei. Computed image analysis using Ki-67 McAb labeling can be used instead of microscopy to determine crypt LI, but neither method can be used to distinguish canter specimens from noncancer spec imens. Copyright (C) 1995 by W.B. Saunders Company