Prognostic factors and overall survival in a 15-year follow-up of patients with malignant salivary gland tumors: a retrospective analysis of 193 patients

Introduction: Malignant tumors of the salivary glands are uncommon pathological entities, representing less than 5% of head and neck neoplasms. The prognosis of patients with malignant tumors of the salivary glands is highly variable and certain clinical factors can significantly influence overall survival. Objective: To analyze the clinicopathologic and sociodemographic characteristics that influence survival in patients with malignant tumors of the salivary glands Methods: This retrospective study analyzed sex, age, race, education level, tumor location, tumor size, lymph node involvement, distant metastasis, margin status, treatment type, marital status, method of health care access and 15-year overall survival in 193 patients with malignant tumors of the salivary glands. The X-2, log-rank Mantel-Cox, multinomial regression and Cox logistic regression tests were used (SPSS 20.0, p < 0.05). Results: The most common histological types were adenocarcinoma (32.1%), adenoid cystic carcinoma (31.1%) and mucoepidermoid carcinoma (18.7%). The 15-year overall survival rate was 67.4%, with a mean of 116 +/- 6 months. The univariate analysis revealed that male sex (p = 0.026), age > 50 years (p = 0.001), referral origin from the public health system (p = 0.011), T stage (p = 0.007), M stage (p < 0.001), clinical stage (p < 0.001), compromised surgical margins (p = 0.013), and chemotherapy (p < 0.001) were associated with a poor prognosis. Multivariate analyses also showed that age > 50 years was independently associated with a poor prognosis (p = 0.016). The level of education was the only factor more prevalent in older patients (p = 0.011). Conclusion: Patients with malignant tumors of the salivary glands older than 50 years have a worse prognosis and an independent association with a low education level.