Introduction
Temporal bone cancers account for around 0.2% of head and neck malignancies and squamous cell carcinoma (SCC) represents the commonest histopathological subtype (1).
Despite its low incidence, temporal bone squamous cell carcinomas (TBSCC) are aggressive with poor survival outcomes and high morbidity. Patients usually present with a troublesome discharging ear, hearing loss, pain, head and neck lumps and not infrequently a facial palsy(2). A combination of biopsies and CT as well as MRI imaging is essential to investigate, diagnose and stage the disease for treatment options. Although there is no Union for International Cancer Control (UICC) or American Joint Committee on Cancer Control (AJCC) on TBSCC, the modified Pittsburgh staging is commonly employed(3).
TBSCC tend to spread locally rather than metastasize to regional lymph nodes or distant sites, making radical resection of the primary lesion the mainstay of treatment. Therefore, while neck dissections (ND) are generally advocated in the presence of nodal disease, although survival of patients with neck metastases is very poor(4), its role in a clinically N0 neck (cN0) has been a subject of debate, mainly due to the lack of evidence and because many units will routinely treat at least the upper neck as well as the primary site with adjuvant radiotherapy. The UK national multidisciplinary guidelines on the management of head and neck cancer(5, 6) have recommended that all TBSCC with cN0 undergo neck dissection of levels 2-5 based on Rinaldo et al.’s narrative review, which estimated that the risk of occult metastases lies between 17-25%.(7) Others may decide on the extent of neck dissection based on the clinical staging, or on performing no neck dissection given that radiotherapy may be planned post-operatively to the neck.
With these discrepancies in mind, the aim of this systematic review and meta-analysis is to estimate the rate of occult cervical metastasis in primary TBSSC and to analyse the evidence on the indication and extent of elective neck dissection in these tumours.