Objective: To analyze nm23-H1 protein immunohistologically in squamous cell carcinoma of the vulva.
Study design: In 68 carcinomas, tumor type, grade, inflammation and vascular space involvement were determined. Formalin-fixed, paraffin-embedded tissue was stained for nm23-H1. Staining pattern, intensity and percentage of stained tumor cells were evaluated. Staining results were analyzed statistically univariately by the chi2 test, Kaplan-Meier survival analysis with log-rank test and receiver operator characteristic curves and multivariately by proportional hazard analysis.
Results: Of the tumors, 9% were negative for nm23-H1. Positive tumors showed 4 staining patterns. Tumors with inhomogeneous expression of nm23-H1 tended to have shorter disease-free and overall survival. Carcinomas with nm23-H1 staining in <50% of the tumor cells more frequently developed nonlocal tumor recurrences (p= 0.018) and showed shorter disease-free survival (p = 0.017). Tumors with high nm23-H1 expression were associated with patients younger than 60 years (p = 0.02).
Conclusion: Immunohistologic staining for nm23-H1 protein shows different staining patterns and percentages of stained cells in squamous cell carcinoma of the vulva. Tumors with inhomogeneous and low nm23-H1 expression are associated with a worse prognosis.