Effect of primary site and treatment modality of patients with head and neck myoepithelial carcinoma on survival

Objective Epidemiological evidence on myoepithelial carcinoma is rare. This study aimed to investigate the effect of tumor primary site and treatment modality on survival in patients with head and neck myoepithelial carcinoma. Methods Data on adult patients diagnosed with head and neck myoepithelial carcinoma between 2000 and 2019 were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Uni- and multivariable Cox proportional hazard models were utilized to evaluate the effects of different tumor primary sites and treatment modalities on overall survival (OS) and cancer-specific survival (CSS), and expressed as hazard ratio (HR) and 95% confidence interval (CI). Results A total of 415 patients were enrolled. No significant differences in OS and CSS were found between different tumor primary sites (P>0.05). Compared with partial excision, patients with total excision (HR=1.65, 95%CI: 1.12-2.42) (partial or total removal of the organ in which the tumor is located and complete removal of the tumor) or no surgery (HR=3.52, 95%CI: 2.05-6.03) had worse OS. Compared with surgery only, patients with radiotherapy only had poorer OS (HR=4.69, 95%CI: 2.32-9.46) and CSS (HR=6.72, 95%CI: 2.59-17.46), while no significant differences in OS (P=0.120) and CSS (P=0.847) were found among patients who received surgery combined with radiotherapy. In patients with AJCC III/IV, patients with radiotherapy only (HR=4.51, 95%CI: 1.61-12.62) had poorer OS compared to those with surgery only, whereas patients who received surgery combined with radiotherapy had better OS (HR=0.50, 95%CI: 0.29-0.89). Conclusion The tumor primary site may not affect the prognosis of patients with myoepithelial carcinoma, while the effect of treatment modality on prognosis is related to the primary site and stage of the tumor.