Nucleic acid flow cytometry in large cell lymphoma.

Between 1978 and 1985, 140 patients with large cell lymphoma (27 follicular, 92 diffuse, 5 immunoblastic, and 16 transformed) had DNA-RNA cytometry performed on involved tissue. DNA-RNA features were correlated with treatment outcome and compared to other established prognostic factors in 63 newly diagnosed patients who received uniformly intensive therapy. Significantly better outcome was noted for previously untreated patients with intermediate RNA content (RNA index, 1.0-1.8), diploid DNA content, and (during the initial 12-month follow-up) low proliferative activity. Of patients followed beyond 12-24 months, those with high proliferative activity appeared to have the most durable remissions, although this was not statistically significant. These findings suggested a preferential impact of intensive chemotherapy on patients with intermediate RNA content and possibly those with high proliferative activity, since previous studies and our own experience with relapsing patients have indicated a progressively worse outlook with higher proliferative activity and RNA index values. In newly diagnosed patients, multivariate analysis identified RNA content as the most important prognostic factor, followed by proliferative activity and serum lactate dehydrogenase. Thus, for patients with large cell lymphoma, DNA-RNA cytometry appears to be a valuable prognostic parameter for identifying a subset of patients who have a high likelihood of cure with intensive chemotherapy.