Expression of Human DNA Topoisomerase II-α in Squamous Cell Carcinoma of the Larynx and Its Correlation With Clinicopathologic Variables

The aggressiveness of laryngeal squamous cell carcinoma (SCC) is unpredictable. Topoisomerase (Topo) II- α is an essential nuclear enzyme; its expression rises at the end of the S-G2/M phase and drops at completion of mitosis. This study sought to determine if Topo II- α expression can serve as a prognostic factor in laryngeal SCC. Specimens from 56 consecutive patients were immunohistochemically stained for Topo II- α , and the number of positive cells in the areas of highest staining was counted in 3 high-power fields (×400) (Topo II- α index). Differences in the Topo II- α index by the presence or absence of recurrence, tumor stage and grade, and disease course were analyzed statistically. On multivariate Cox regression analysis, the Topo II- α index (>70 or ≤70) ( P = .008) and tumor grade ( P = .034) independently predicted disease-free survival. These findings suggest that high Topo II- α expression may be a useful indicator of tumor aggressiveness and poor outcome in laryngeal SCC.