Squamous cell carcinoma variants in the major salivary glands: a population-based study

Primary squamous cell carcinoma (SCC) of the major salivary glands is a rare malignancy with poor prognosis. Histological variants may differ in clinical presentation and outcomes.

To clarify the clinicopathological features and prognostic impact of SCC variants in the major salivary glands using a large population-based dataset.

We analysed 3581 patients with primary salivary gland SCC. Variants included conventional SCC, lymphoepithelial carcinoma (LEC), basaloid SCC (BSCC), and spindle cell carcinoma (SpCC). Overall survival (OS) and disease-specific survival (DSS) were evaluated by the Kaplan-Meier method and Cox regression analyses.

Conventional SCC accounted for 92.7% of cases, followed by LEC (3.7%), BSCC (1.7%), and SpCC (1.3%). The 5-year OS rates were 39.0% for conventional SCC, 76.4% for LEC, 51.5% for BSCC, and 41.8% for SpCC (p < 0.001). The corresponding DSS rates were 60.0%, 85.6%, 62.7%, and 64.9% (p < 0.001). In multivariate analysis, LEC was independently associated with superior survival, with hazard ratios of 0.50 (95% confidence interval (CI) 0.36-0.71) for OS and 0.46 (95% CI 0.28-0.74) for DSS, whereas BSCC and SpCC showed outcomes comparable to conventional SCC.

Histological variant is a significant prognostic factor in salivary gland SCC. LEC showed favourable survival.