DNA CONTENT AND CELL-KINETICS IN COLORECTAL-CARCINOMA - FLOW CYTOMETRIC ANALYSIS OF PRIMARY TUMOR AND LIVER METASTASES

Aims and background: Both flow cytometric DNA ploidy and proliferative activity have been indicated as potential prognostic indicators in co lorectal cancer. Due to tumor biological heterogeneity, these paramete rs are best assessed with multiple sampling. Methods: We undertook a p rospective study on 52 patients with Duke's D colorectal tumors lookin g at multiple samples of the primary tumors and liver metastases. DNA ploidy and tumor proliferative activity (derived from proliferating ce ll nuclear antigen, PCNA FCM expression) were evaluated. Results: Of p rimary tumors, 36/52 (69,2%) were aneuploid in at least 1 sample, with a median value of the DNA index of the aneuploid peak of 1.58. On liv er metastases, 42/52 (80,7%) patients were aneuploid in at least 1 sam ple with a median DNA index of the aneuploid peak of 1.64. Identical o r nearly identical histograms from different tumor samples were observ ed in only 18/52 (34.6%) of the primary tumors and in 15/52 (28.8%) of the liver metastases. The PCNA values for primary tumors ranged from 5 to 28% (median value = 16.5%). In the liver metastases, PCNA values ranged from 12 to 38% (median value = 19.8%). Proliferative activity w as lower for diploid than for aneuploid tumors. DNA ploidy and PCNA ex pression of the deep specimen of primary tumors were similar to those of the liver metastasis of the same patient while this concordance was not complete in the case of superficial biopsy specimens. Conclusions : If correctly performed, FCM techniques allow an accurate analysis of DNA ploidy and proliferative activity and both these measurements can offer considerable potential for a more comprehensive approach to col orectal cancer.