Flow cytometric DNA-ploidy and proliferative activity of diethylnitrosamine-induced hepatocellular carcinoma and pulmonary metastases in monkeys.

Flow cytometric DNA analysis was carried out on diethylnitrosamine (DEN) induced primary hepatocellular carcinomas (HCC) and lung metastases in monkeys. In analyzing one sample from each of 133 HCC cases, 76 (67.2%) were diploid and 37 (32.7%) aneuploid. When more samples were analyzed from the same tumorous liver, all of the 76 diploid cases maintained their pattern, whereas 5 (13.5%) of the aneuploid cases displayed both diploid and aneuploid DNA. Studies of lung metastases from 44 (28 diploid, 16 aneuploid) HCC cases showed that the DNA-ploidy pattern characterizing the primary HCC was preserved in the metastases in 78.6% of the diploid and 93.7% of the aneuploid cases. The average synthetic phase fraction (SPF) value for the diploid tumors was 7.7% and the aneuploid tumors 14.9%. The difference is highly significant (P < .01). Highly significant correlation was found between the DNA ploidy and the SPF values, both in the primary HCC (P = .0001) and the metastases (P = .0266). Of different tumor and host features examined, statistically significant correlation was only found between DNA-ploidy/SPF and the cytological tumor grade. This study represents the first DNA-ploidy analysis of HCC in monkeys. The data showed that diploid and aneuploid tumors displayed comparable metastatic potential. The DNA-ploidy pattern was preserved in the metastases in the majority of the cases.