Comparative impact of grade on mortality across salivary cancers: A novel, unifying staging system

Allen S Ho; Michael Luu; Bonnie L Balzer; Katri Aro; Julie K Jang; Alain C Mita; Kevin S Scher; Jon Mallen-St Clair; Missael Vasquez; Amanda J Bastien; Joel B Epstein; De-Chen Lin; Michelle M Chen; Zachary S Zumsteg

doi:10.1002/hed.27429

Comparative impact of grade on mortality across salivary cancers: A novel, unifying staging system

Head Neck. 2023 Aug;45(8):2028-2039. doi: 10.1002/hed.27429. Epub 2023 Jun 22.

Authors

Allen S Ho^{1

2}, Michael Luu^{1

3}, Bonnie L Balzer^{1

4}, Katri Aro⁵, Julie K Jang^{1

6}, Alain C Mita^{1

7}, Kevin S Scher^{1

7}, Jon Mallen-St Clair^{1

2}, Missael Vasquez², Amanda J Bastien², Joel B Epstein¹, De-Chen Lin⁸, Michelle M Chen^{1

2}, Zachary S Zumsteg^{1

6}

Affiliations

¹ Samuel Oschin Comprehensive Cancer Institute, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
² Division of Otolaryngology - Head and Neck Surgery, Department of Surgery, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
³ Biostatistics and Bioinformatics Research Center, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
⁴ Department of Pathology, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
⁵ Department of Otorhinolaryngology - Head and Neck Surgery, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.
⁶ Department of Radiation Oncology, Cedars-Sinai Medical Center, Los Angeles, California, USA.
⁷ Division of Medical Oncology, Department of Medicine, Cedars-Sinai Medical Center, Los Angeles, California, USA.
⁸ Herman Ostrow School of Dentistry, University of Southern California, Cedars-Sinai Medical Center, Los Angeles, California, USA.

PMID: 37345665
DOI: 10.1002/hed.27429

Abstract

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.

Keywords: grade; head and neck cancer; histologic variant; salivary cancer; staging.

MeSH terms

Adenoma, Pleomorphic* / pathology
Carcinoma, Acinar Cell* / pathology
Carcinoma, Adenoid Cystic*
Carcinoma, Mucoepidermoid* / pathology
Humans
Salivary Gland Neoplasms* / pathology