Prognostic significance of DNA cytometry in thymoma

Abstract

 Purpose: The aim of this work was to evaluate the prognostic significance of DNA image cytometry in thymoma. Patients and methods: Image cytometric studies with an automatic video-based analysis system (LEYTAS) were carried out on 47 archival specimens from 36 patients with thymomas who underwent operation at a single institution from 1954 to 1992. The significance of aneuploidy DNA-content (5c-exceeding events), and nuclear size on stage and survival were evaluated. The median follow-up was 52.7 (6–164) months. Results: Masaoka's stage was predictive of aneuploidy (P < 0.01) and disease-free survival (P < 0.015). In stage I 18% of the tumors were aneuploid, in stage II 78%, in stage III 85% and in stage IV 100%. The occurrence of 5c-exceeding events was associated with both decreased disease-free survival (P < 0.01) and overall survival (P = 0.013). Nuclear size was not significantly correlated to stage. Under multivariate analysis, aneuploidy and DNA content failed to attain independent significance for stage, performance status, and histology. Conclusion: DNA image cytometry may provide additional information about the prognosis of resected thymoma.