Most Common Submandibular Gland Cancer
Adenoid cystic carcinoma is the most common malignant tumor of the submandibular gland, accounting for approximately 36% of cases, followed by squamous cell carcinoma (18%) and mucoepidermoid carcinoma (17%). 1
Epidemiology and Histologic Distribution
The submandibular gland represents the second most common site for salivary gland tumors after the parotid, but carries a significantly higher risk of malignancy due to its smaller size—approximately 50% of submandibular tumors are malignant compared to much lower rates in the parotid. 2, 3
Key histologic types in order of frequency:
- Adenoid cystic carcinoma: 36% - This is the single most common malignant histology 1
- Squamous cell carcinoma: 18% 1
- Mucoepidermoid carcinoma: 17% 1
- Adenocarcinoma: 14% 1
- Other rare types including salivary duct carcinoma and carcinoma ex pleomorphic adenoma 4, 5
Clinical Significance
The inverse relationship between salivary gland size and malignancy risk makes submandibular lesions particularly concerning—any submandibular mass warrants aggressive diagnostic workup. 2
Critical prognostic factors that affect survival include:
- Tumor stage at presentation (higher stage = worse prognosis) 1
- Histologic grade (high grade = decreased survival) 4, 1
- Tumor size >3 cm (significantly worse prognosis above this cutoff) 1
- Surgical resection margins (positive margins = poor locoregional control) 4
- Age and sex (older age and male sex = worse outcomes) 1
High Propensity for Systemic Failure
Approximately one-third (34%) of submandibular gland carcinomas develop distant metastases, most commonly to the lungs (up to 90% of distant disease), despite effective locoregional treatment. 6, 4 This high rate of systemic failure results in poor overall survival—only 56.8% at 5 years and 40% at 10 years. 4, 1
The majority of recurrences (70%) occur within the first 3 years following treatment, with local recurrence in 13%, regional recurrence in 22%, and distant metastases in 33% of cases. 6