The flow cytometric analysis of premalignant and malignant lesions in head and neck squamous cell carcinoma

SummaryWe attempted to identify the molecular mechanisms involved in Head and Neck Squamous Cell Carcinoma (HNSCC) pathogenesis by measuring the nuclear DNA content (ploidy) in premalignant (potentially malignant) and malignant patients as compared to normal controls, and to determine whether DNA ploidy could be used to predict the clinical outcome. From March 2001 to December 2003, the analysis was carried out in a set of 41 patients with premalignant lesions and 79 suffering from squamous cell carcinoma of laryngeal, oesophageal, nasopharyngeal, nasal and oral lesions and 50 controls. Representative samples were taken by punch biopsy and processed using standard formol-paraffin technique for histopathological examination. Fifty micrometer thick sections of paraffin-embedded tissues were analyzed to detect the DNA content by image cytometry. Of the potentially malignant patients, 46% had diploid lesions, 37% had tetraploid lesions and 17% had aneuploid lesions. While of the patients with cancer, 90% had aneuploid lesions, 10% had diploid lesions and none had tetraploid lesions. DNA diploidy tended to occur earlier in the progression from premalignant to malignant lesions and this helps us early detection of HNSCC by DNA from lesions in high risk groups and examination of its ploidy. Knowledge of tumor cell ploidy by DNA image cytometry may facilitate the evaluation of malignant and premalignant lesions in HNSCC. The present findings are promising to supplement clinical and histopathological parameters in evaluating prognosis and to demonstrate methods that are readily applicable for routine diagnostic work.