Prognostic indicators in clinically node-negative malignant primary salivary tumours of the parotid: A multicentre experience.

OBJECTIVES: Nodal metastasis is an important prognosticator in primary parotid cancers. The management of the clinically node-negative neck is an area lacking consensus. This study investigates the occult nodal metastasis rate, and prognostic indicators in primary parotid cancers. MATERIALS AND METHODS: We performed a multicentre retrospective case note review of patients diagnosed and treated surgically with curative intent between 1997 and 2020. Demographic, clinic-pathological and follow-up data was recorded. RESULTS: After exclusions, 334 patients were included for analysis, with a median follow-up of 48 months. The overall rate of occult lymph node metastasis amongst patients undergoing elective neck dissection was 22.4%, with older age, high-grade and more advanced primary tumours being associated with higher rates. On multivariable analysis, age ≥ 60 years (HR = 2.69, p = 0.004), high-grade tumours (HR = 2.70, p = 0.005) and advanced primary tumours (pT3-4, HR = 2.06, p = 0.038) were associated with worse overall survival. Occult nodal metastasis on final pathology was associated with a close-to-significant reduction in regional recurrence free survival (HR = 3.18, p = 0.076). CONCLUSION: This large series confirms the significant occult lymph node metastasis rate in primary parotid cancer, and demonstrates the importance of primary histology, tumour grade and stage in predicting survival outcome. This data supports the use of elective neck dissection in patients with high-risk tumours.

Intraoperative Primary Tumor Identification and Margin Assessment in Head and Neck Unknown Primary Tumors.

OBJECTIVE: Surgical management of the unknown primary head and neck squamous cell carcinoma (UP HNSCC) remains controversial due to challenging clinical diagnosis. This study compares positron emission tomography-computed tomography (PET-CT) findings with intraoperative identification of primary tumors and compares intraoperative frozen-section margins to final histopathology. In addition, adjuvant therapy indications are provided. STUDY DESIGN: Prospective cohort study. SETTING: Academic university hospital. SUBJECTS AND METHODS: Sixty-one patients with UP HNSCC were included. Patients received PET-CT, followed by oropharyngeal transoral laser microsurgery (TLM). Margins were assessed intraoperatively using frozen sections and afterward by final histopathology. Adjuvant treatment was based on final histopathology. RESULTS: The sensitivity of localizing the primary tumor with PET-CT was 50.9% with a specificity of 82.5%. The primary tumor was found intraoperatively on frozen sections in 82% (n = 50) of patients. Five more tumors were identified on final histopathology, leading to a total of 90% (n = 55). Of the 50 intraoperatively found tumors, 98% (n = 49) had negative margins on frozen sections, and 90% (n = 45) were truly negative on final histopathology. Eighteen patients (29.5%) avoided adjuvant treatment. CONCLUSION: PET-CT localized the primary tumor in fewer than half the cases. This protocol identified 90% of primary tumors. Intraoperative frozen-section margin assessment has shown potential with a specificity of 92% compared to final histopathology. As a result, adjuvant therapy was avoided in almost one-third of our patients.