Histopathologic prognostic factors in resected adenocarcinomas: is nuclear DNA content prognostic?

The pathobiological characteristics of lung adenocarcinoma are still unclear. To identify the factors that may affect the survival of patients undergoing pulmonary resections for adenocarcinoma of the lung, univariate and multivariate analyses were performed for 17 variables of the host, histopathology, nuclear DNA content (NDC), and morphometry of nucleus (nuclear area [NA]) of tumor cells.

Seventy-two consecutive patients who underwent resection at the National Cancer Center in Tokyo were studied. They consisted of 45 men and 27 women with an average age of 61.7 years (range, 27 to 83 years). For these patients, NDC and NA were prospectively measured by cytofluorometry and morphometry, respectively. For univariate analysis, 17 factors were studied, including age, sex, TNM stage, diameter of the tumor, pleural involvement, degree of differentiation, scar grade, nuclear atypia, mitotic index, histogram pattern of NDC, mean NDC, number of aneuploid stem cell lines, and mean and SD of NA. A multivariate analysis was performed with Cox's regression model for 16 variables.

In the univariate analysis, 12 factors were significantly related to postoperative survival, including TNM stage, diameter, pleural involvement, nuclear atypia, mitotic index, mean NA, mean NDC, number of aneuploid stem cell lines, and the DNA histogram pattern. In the multivariate analysis, M, T, and the histogram pattern of NDC were significantly associated with survival while N showed a strong, but not significant, association.

Multivariate analysis of histopathologic prognostic factors indicated that the TNM stage, as well as each component independently, still provided the greatest prognostic value in resected adenocarcinomas of the lung. Among other factors, only NDC significantly affected survival. The importance of NDC measurement should be stressed for predicting the survival after surgical resection more accurately and for selecting patients with a higher risk of recurrence.