Autoradiographic and flow‐cytometric assessment of cell proliferation in primary colorectal cancer: Relationship to dna ploidy and clinico‐pathological features

Two cell‐kinetic parameters, the [ 3 H]thymidine‐labeling index [ 3 H]dT LI and the flow‐cytometric S‐phase cell fraction (FCM‐S), and DNA ploidy were determined for a prospective series of 110 primary colorectal cancers. Aneuploidy was observed in 66% of tumors and more than one aneuploid peak was present in 12%. The frequency of aneuploid tumors was higher in rectal (80%) and left‐colon (70%) cancers than in right‐colon cancers (51%), and multiple aneuploid clones were detected more frequently in men than in women ( p = 0.03) and more frequently in advanced Dukes' D‐stage patients ( p = 0.08). The median [ H]dT LI value (17.4%) was similar to the FCM‐S value determined by a planimetric model (16.2%) and somewhat higher than the FMC‐S value obtained by an optimization procedure (11.2%). However, there was no significant relationship between the [ 3 H]dT LI value and either FCM‐S value for individual tumors. Moreover, FCM‐S values were higher in aneuploid than in diploid tumors, whereas [ 3 H]dT LI values were independent of DNA‐ploidy status; [ 3 H]dT LI and FCM‐S were also related differently to some clinical and pathological features such as tumor site and histology. These findings suggest different biological meanings for these 2 cell‐kinetic parameters, which should not be used interchangeably.