Patterns of Cervical Metastases and Implications for Neck Management in Minor Salivary Gland Cancer Treatment.

Abstract

Objectives: Minor salivary gland cancer (MiSGC) is a rare and heterogeneous disease, with different degrees of tumor aggressiveness. The scarce data in the literature show that the presence of lymph node metastases (LNMs) negatively impacts the prognosis. Furthermore, there is a lack of information about the patterns and extension of LNMs in MiSGC. Therefore, it is necessary to identify the clinical and pathological features associated with LNMs in MiSGC to guide the cervical dissection intent of those patients. This study's endpoints were the identification of clinicopathological features associated with LNMs, identification of spread patterns of clinical and occult LNMs, and the impact of LNMs on the patient's outcome.

Materials and methods: This single-center retrospective cohort study analyzed data from 437 patients with MiSGC of the oral cavity and oropharynx treated at the Instituto Nacional de Câncer (INCA), the Brazilian National Cancer Institute.

Results: LNMs were observed in 59 patients (13.5%). Cervical levels I and II were the most affected neck levels in the total sample, and in MiSGC of the oral cavity, whereas Levels II and III were the most affected in MiSGC of the oropharynx. Adenocarcinoma histotype, floor of the mouth and base of the tongue subsites, late-stage tumor, and lymphovascular invasion were associated with LNMs. LNMs were associated with worse overall and disease-specific survival rates.

Conclusion: There are LNMs spread specific to the site of the MiSGC, with an impact on the patient's prognosis. Adenocarcinoma, tumor subsite, and lymphovascular invasion were associated with LNMs.