Prognostic significance of tumor proliferative fraction and DNA content in stage I non-small cell lung cancer.

Analyses of tumor DNA content and proliferative fraction by flow cytometry have been useful as prognostic determinants in a variety of solid tumors. The significance of this analysis in Stage I (T1N0M0 and T2N0M0) non-small cell lung carcinoma (NSCC) is unestablished. We determined DNA content (ploidy) and proliferative fraction (percentage S phase) on 44 surgically resected Stage I NSCC specimens obtained between 1977 and 1982. All cases had a minimum follow-up of 5 yr. Of the 44 cases, 27 were adenocarcinomas, 15 squamous cell carcinomas, and 2 large cell carcinomas. Of these, 32 (73%) had T1N0M0 lesions and 12 (27%) had T2N0M0 lesions. Overall 5-yr survival was 70%. All patients surviving 5 yr were free of detectable tumor. Patients with T1N0M0 lesions had an 81% 5-yr survival, but those with T2N0M0 lesions had a 42% 5-yr survival (p = 0.009). Analysis of tumor DNA content revealed 35 diploid tumors (79%) and 9 aneuploid tumors (21%). The 5-yr survival for diploid tumors was 77% compared with a 44% 5-yr survival in aneuploid lesions (p = 0.048). The median proliferative fraction was 6%. All patients with a percentage S phase less than 6% survived 5 yr, and 41% (9 of 22) of those greater than 6% survived 5 yr (p less than 0.001). When 8% S phase was used as a cutoff, 93% (28 of 30) below the cutoff survived 5 yr but only 21% (3 of 14) above the cutoff survived 5 yr (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)