Expression of PTEN protein in patients with laryngeal squamous cell carcinoma

Objective PTEN (phosphatase and tensin homologue deleted on chromosome 10), also referred to as MMAC1 (mutated in multiple advanced cancers) gene was recently identified as a putative tumor suppressor in a variety of malignant tumors. PTEN expression has been investigated in some squamous cell carcinomas (SCC) of head and neck. However, there is only little knowledge about laryngeal malignancies. Therefore, we examined PTEN product protein immunohistochemically in 30 consecutive laryngeal specimens from patients with laryngeal SCC and compared the results according to the clinicopathologic characteristics of the patients. Method Surgical resection specimens of patients with laryngeal SCC were stained for PTEN protein using a primary rabbit polyclonal anti-PTEN antibody. Standard avidin–biotin immunohistochemical analysis was used to process the sections. The extent and intensity of PTEN staining in the specimens were compared according to the age and sex of the patients and localization, differentiation, size and stage of the tumor. Results Out of 30 tumoral specimens (23 glottic and 7 supraglottic) 22 showed decreased PTEN staining intensity compared to the adjacent normal tissue. The extent of cytoplasmic PTEN staining was significantly less in supraglottic tumors (p < 0.05). When characteristics of the patients were analyzed according to the extent of cytoplasmic PTEN staining no difference was observed according to age, sex, measure, differentiation, T or N status. Conclusion A significant decrease in the extent of PTEN staining was observed in supraglottic SCC. It could be worthwhile to test if PTEN expression is diminished in patients with more aggressive laryngeal tumors, with special attention to tumor localization in larger series.