Is Ki67 a marker for the transformation of laryngeal dysplasia to carcinoma?

Abstract

Conclusion. Ki67 is not a reliable marker of malignant transformation in laryngeal dysplasia.

Objectives. No reliable means of predicting which cases of laryngeal dysplasia will undergo malignant transformation currently exists. Our aim was to evaluate Ki67, a marker of cell proliferation, as a potential marker for the transformation of laryngeal dysplasia to squamous cell carcinoma.

Patients and methods. Eighty consecutive cases of previously untreated patients with a histological diagnosis of laryngeal dysplasia from 1987 to 1993 were identified from the pathological archives. Standard immunohistochemical techniques were used to identify Ki67-positive cells and activity was scored on a scale of 0–4 using defined criteria.

Results. Of the 80 cases there were 24 females and 56 males with a mean age of 56 years (range 29–80 years). Twenty cases subsequently transformed to a squamous cell carcinoma. For each Ki67 score (0–4), the rate of malignant transformation was: 0, 1 of 6 patients (17%); 1, 7 of 33 patients (21%); 2, 5 of 22 patients (23%); 3, 4 of 13 patients (31%); and 4, 3 of 6 patients (50%). A higher Ki67 score seemed to correlate with a higher likelihood of malignant transformation but this did not reach statistical significance (p = 0.17, Pearson χ² test). Considering a score of 3 or 4 as positive for predicting malignant transformation produced a test of relatively high specificity (80%) but poor sensitivity (35%).

• Larynx
• dysplasia
• carcinoma
• Ki67