Risk of Cervical Metastasis in Primary Parotid Gland Malignancies: A Yo-IFOS Multicenter Retrospective Longitudinal...

Area of Science:

• Oncology
• Head and Neck Surgery
• Pathology

Background:

• Cervical lymph node metastasis is a critical prognostic factor in parotid gland malignancies.
• Current understanding of nodal metastasis incidence, distribution, and predictors in large cohorts is limited.

Purpose of the Study:

• To define the incidence, level-specific distribution, and independent predictors of cervical lymph node metastasis in primary parotid gland carcinoma.
• To evaluate the impact of nodal metastasis on survival outcomes.

Main Methods:

• Retrospective analysis of 380 adult patients with primary parotid gland carcinoma across 17 centers.
• Inclusion criteria: histopathologically confirmed carcinoma, parotidectomy with neck dissection.
• Primary outcome: pathological cervical lymph node metastasis; Secondary outcomes: nodal distribution, risk factors, overall survival (OS), disease-specific survival (DSS).

Main Results:

• Cervical lymph node metastasis was found in 24.7% of patients.
• Level II was the most frequent site of metastasis (IIa 17.1%, IIb 11.1%).
• Salivary duct carcinoma had the highest metastasis rate (58.7%). High histological grade and lymphovascular invasion (LVI) were independent predictors (p<0.05). Five-year OS was 64.4%, significantly lower for node-positive patients (p<0.001).

Conclusions:

• Approximately 25% of surgically staged parotid malignancies exhibit cervical lymph node metastasis, mainly in Levels II-III.
• High-grade histology and LVI are independent predictors of nodal involvement.
• Findings support a risk-adapted approach for elective neck treatment based on pathological risk stratification.