Zachary S. Zumsteg

Background The comparative impact of histologic variants and grade has not been well described. Methods Salivary cancer histologies were profiled using hospital and population‐based cancer registries. Multivariable models were employed to assess relationships between histology, grade, and survival. Results On univariate analysis, histologic variants exhibited a wide spectrum of mortality risk (5‐year overall survival (OS): 86% (acinic cell carcinoma), 78% (mucoepidermoid carcinoma), 72% (adenoid cystic carcinoma), 64% (carcinoma ex‐pleomorphic adenoma), 52% (adenocarcinoma NOS), and 47% (salivary duct carcinoma) ( p < 0.001). However, on multivariable analysis these differences largely vanished. Worsening grade corresponded with deteriorating survival (5‐year OS: 89% [low‐grade], 81% [intermediate‐grade], 45% [high‐grade]; p < 0.001), which was upheld on multivariable analysis and propensity score matching. Recursive partitioning analysis generated TNM + G schema (c‐index 0.75) superior to the existing system (c‐index 0.73). Conclusion Grade represents a primary determinant of salivary cancer prognosis. Integrating grade into stage strengthens current staging systems.