THE LEVEL OF CERVICAL LYMPH-NODE METASTASES - THEIR PROGNOSTIC RELEVANCE AND RELATIONSHIP WITH HEAD AND NECK SQUAMOUS CARCINOMA PRIMARY SITES

It would seem logical that patients with nodal metastases low in the neck would fare less well than patients with disease high in the neck. The penultimate UICC classification suggested that neck node level was important although there was no mention of this in the most recent classification. In addition, patients with carcinomas at the various sites would be expected to have different patterns of nodal involvement. Of 3419 patients with head and neck squamous carcinoma on the Liverpool University Head and Neck Unit database, 947 had neck node metastases. The neck node levels were coded as (I) sub-mandibular, (II) above the thyroid notch, (III) below the thyroid notch and (IV) supra-clavicular/posterior triangle nodes. Levels II and III contained the deep jugular chain. The relationship between node level and site and sub-site and survival were analysed with particular emphasis on multivariate methods. The 5-year survival for the whole group was 51% and survival fell with decreasing node level (I-IV) being 37% for sub-mandibular nodes, 32% for deep cervical nodes and 25% for lower deep cervical nodes. The 18-month survival for supra-clavicular and posterior triangle nodes was 21%. The difference in survival was significant (chi3(2) = 24.42, P < 0.001). Multivariate analysis confirmed that as the level of the nodes fell from the sub-mandibular region to the supra-clavicular region the prognosis worsened (estimate = -0.3378, P = 0.0003). Level II (upper deep cervical) nodes were the most commonly involved with regards to all primary sites and formed 69% of all neck node metastases. Over three quarters of laryngeal oropharyngeal and hypopharyngeal metastases went to this level whereas only 47% of oral cancers did. Most of the remainder of these latter lesions metastasized to level 1 (42%). These findings were confirmed by multiple logistic regression. When studying survival for lymph node level with regard to site all sites had a reducing prognosis with decreasing node level except for larynx. Multiple linear regression showed an association between decreasing node level and increasing N-stage (P = 0.001) with increasing T-stage (P = 0.0014) and as the site moved from the mouth to the larynx (P = 0.0047). The present data support the view that neck node level is important as regards prognosis for most sites in the head and neck. The data confirm the clinical view that deep cervical nodes are most frequently affected by head and neck cancer with level IV nodes being unusual and clinically tending to herald a non head and neck tumour and that level III nodes are relatively uncommon. This is surprising as one would expect at least a proportion of laryngeal carcinomas and quite a high proportion of hypopharyngeal carcinomas to metastasize to this region.