DNA cytofluorometric and nuclear morphometric analyses of lung adenocarcinoma

The nuclear DNA content of tumor cells in imprint smears prepared from 72 surgically resected adenocarcinomas of the lung was determined prospectively by means of cytofluorometry, and its relationship to pathologic stage, degree of histologic differentiation, and nuclear atypia represented by the mean nuclear area (MNA) and standard deviation of the nuclear area (SDNA) was studied. The mean nuclear DNA content (MNDC) of poorly differentiated adenocarcinomas was significantly larger than that of well-differentiated adenocarcinomas both in Stages I + II and III + IV (P less than 0.001, each), and the MNDC of Stages III + IV was significantly larger than that of I + II in poorly differentiated adenocarcinomas (P less than 0.01). There was a tendency for histogram Patterns III and IV, in which more aneuploid cells were present than in I and II, to be more common and for the incidence of the aneuploid stem cell line to be higher in less differentiated and more advanced adenocarcinomas, although the differences were not significant statistically. Furthermore, there were significant positive correlations between MNDC and MNA (P less than 0.01) and between MNDC and SDNA (P less than 0.05). The averages of the MNA according to the histogram pattern increased significantly in the increasing order of Patterns I to IV. These results indicate that the nuclear DNA content increases in less differentiated and more advanced adenocarcinomas, and that the nuclear atypia is reflected in abnormal nuclear DNA content (DNA aneuploidy).