Prognostic significance of nuclear DNA content in small cell carcinoma of the lung.

The relationship between the nuclear DNA histogram patterns of tumor cells obtained by brushing via bronchoscopy and the survival time of 39 patients with small cell carcinoma of the lung was investigated. The brushing smears were stained by a modified Feulgen method. The nuclear DNA content was measured at 550 nm using a microspectrophotometer. The DNA histogram pattern was classified into type I, which contained a higher proportion of G0G1-phase cells, and type II, which contained a higher proportion of S, G2M-phase cells. The median survival times for the patients with limited disease of type I, type II and the patients with extensive disease of type I, type II were 17.2 months, 10.2 months, 10.0 months, and 5.6 months, respectively. Patients with limited disease of type I had a significantly longer survival time than patients with limited disease of type II. A distinct correlation was found between the histogram pattern and the survival of the patients. These results indicated that the nuclear DNA histogram pattern may be an indicator to allow speculation as to the prognosis of patients with small cell carcinoma of the lung.