Mu-Opioid Receptor Expression in Laryngeal Cancer

Objectives: Expression of mu-opioid receptors (MORs) has not been investigated in head and neck cancer. In this study, we aimed to assess the expression of opioids receptors in laryngeal cancer, compared to adjacent non-malignant tissue. Study design: A retrospective case series in a single academic center. Methods: Sixty-four specimens were taken from 32 matched patients, diagnosed with laryngeal-carcinoma (20 supraglottic and 12 glottic), and were analyzed using immunohistochemical stains for MOR. All sections were examined and evaluated with a semi-quantitative analysis for staining intensity and cell count for a percentage of the positively stained cells. Survival of patients was compared based on MOR expression. Results: MOR staining intensity was significantly increased in laryngeal-carcinoma compared to the normal tissue adjacent to the carcinoma (P = 0.019). The percentage of stained cells in non-involved supraglottis was significantly higher compared to the non-involved glottis (P = 0.022), yet this difference was no longer found between supra- and glottic-carcinoma tissues. Conclusion: MOR may play a role in the laryngeal cancer environment, as the expression in tumor cells alters from adjacent non-cancerous tissue.