Survival and prognostic factors of salivary gland malignant mixed tumor-not otherwise specified: A population-based analysis

• Published in: American journal of otolaryngology Vol. 42; no. 6; p. 103135
• Main Authors: Soffer, Justin M., Nassif, Samih J., Von Plato, Michael, Chisholm, Jaime, O'Leary, Miriam A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.11.2021; Elsevier Limited
• Subjects: Adenoma; Adenoma, Pleomorphic - epidemiology; Adenoma, Pleomorphic - mortality; Adenoma, Pleomorphic - pathology; Adenoma, Pleomorphic - therapy; Age; Chemotherapy; Demographics; Diagnosis; Divorce; Epidemiology; Ethnicity; Exocrine glands; Facial nerve; Female; Hispanic people; Humans; Lymph nodes; Lymph Nodes - pathology; Lymphatic system; Male; Malignant mixed tumor; Malignant mixed tumor-not otherwise specified; Medical prognosis; Metastases; Metastasis; Middle Aged; Mixed Tumor, Malignant - epidemiology; Mixed Tumor, Malignant - mortality; Mixed Tumor, Malignant - pathology; Mixed Tumor, Malignant - therapy; Mortality; Multivariate analysis; Neoplasm Staging; Neoplasms; Oral cancer; Otolaryngology; Patients; Prognosis; Prognostic factors; Radiation; Regression analysis; Retrospective Studies; Salivary gland; Salivary Gland Neoplasms - epidemiology; Salivary Gland Neoplasms - mortality; Salivary Gland Neoplasms - pathology; Salivary Gland Neoplasms - therapy; Salivary glands; Salivary Glands - pathology; SEER; SEER Program; Surgery; Survival; Survival analysis; Survival Rate; Tumors; United States > US; Malignant mixed tumor-not otherwise specified; Salivary gland; SEER; Malignant mixed tumor; Survival; Prognostic factors
• DOI: 10.1016/j.amjoto.2021.103135
• ISSN: 0196-0709

Malignant mixed tumors of the salivary gland are a group of neoplasms comprised of carcinoma-ex-pleomorphic adenoma, carcinosarcoma, and metastasizing pleomorphic adenoma. An alternative classification, malignant mixed tumor-not otherwise (MMT-NOS), is a diagnosis of exclusion for neoplasms that do not fit the previous histologically profiled subtypes. The objective was to provide a comprehensive assessment of MMT-NOS and determine prognostic factors. This retrospective cohort study queried the Surveillance, Epidemiology, and End Results database for patient and tumor characteristics of US patients with MMT-NOS of the major salivary glands from 1973 to 2016. Kaplan-Meier and Cox regression analysis were performed to determine 5-year survival and prognostic factors. 434 patients were identified with a mean age at diagnosis of 61.5 years. The majority of neoplasms were high grade and stage (70.8% grade III/IV; 63.8% stage III/IV). Extraparenchymal extension (40.6%) and lymph node involvement (28.5%) were common; distant metastases (2.4%) were rare. Treatment included surgery (93.0%), radiation (51.6%), and chemotherapy (10.4%). Facial nerve sacrifice was common (50.8%). Median survival was 66.5 months. 5-year overall and disease-specific survival were 65.7% and 83.0%, respectively. In multivariate analysis, nodal involvement (HR 7.0; P < 0.001), surgery-radiation-chemotherapy (HR 6.1; P = 0.02), extraparenchymal extension (HR 2.50; P = 0.04), and tumor size >4 cm (HR 1.3; P = 0.03) were prognostic factors. Despite high stage and grade at diagnosis, MMT-NOS portends a good 5-year prognosis and low rate of distant metastasis. Prognostic factors were nodal involvement, tumor size, and extraparenchymal extension.