[Analysis of DNA content in primary colorectal carcinoma and lung metastasis]

We analyzed DNA content of resected primary colorectal carcinoma and lung metastasis by flow cytometry. Of the 14 primary lesions, 5 cases showed diploid pattern, 9 cases aneuploid pattern. In contrast, 12 metastatic lung lesions of 19 showed diploid pattern and 7 lesions aneuploid pattern. DNA index of primary and metastatic lesions was 1.4 +/- 0.4 and 1.2 +/- 0.2, respectively (p = 0.08). In combination of DNA ploidy pattern between primary and metastatic lesions, there were 11 in which ploidy pattern was identical, 1 in which metastasis was aneuploid and primary was diploid, 7 in which metastasis was diploid and primary was aneuploid. Four year, survival rate from operation of metastasis was better in diploid pattern than in aneuploid pattern, but it was not significant. These results indicate that patients who have operative indication of metastasis from colorectal carcinoma have metastatic tumor which shows relatively good biological behavior (diploid tumors) and that there are heterogeneity of ploidy pattern between primary and metastatic lesions.