Nodal metastasis is an important prognostic factor in head and neck squamous cell carcinoma. This study aimed to determine the average nodal basin yield per level of neck dissection, and to investigate if age, gender, body mass index, tumour size, depth of tumour invasion and p16 status influence nodal yield.

A retrospective review of 185 patients with head and neck squamous cell carcinoma generated 240 neck dissection specimens.

The respective mean nodal yields for levels I, II, III, IV and V were 5.27, 9.43, 8.49, 7.43 and 9.02 in non-cutaneous squamous cell carcinoma patients, and 4.2, 7.57, 9.65, 4.33 and 12.29 in cutaneous squamous cell carcinoma patients. Multiple regression analysis revealed that p16-positive patients with mucosal squamous cell carcinoma yielded, on average, 2.4 more nodes than their p16-negative peers (p = 0.04, 95 per cent confidence interval = 0.116 to 4.693). This figure was 3.84 (p = 0.008, 95 per cent confidence interval = 1.070 to 6.605) for p16-positive patients with oral cavity squamous cell carcinoma.

In mucosal squamous cell carcinoma, p16-positive status significantly influenced nodal yield, with the impact being more pronounced in oral cavity squamous cell carcinoma patients.

This study aimed to link expression patterns of AQP1, AQP5, Bcl-2 and p16 to clinicopathological characteristics of oro-hypopharyngeal squamous cell carcinomas.

Immunohistochemical expression of AQP1, AQP5, Bcl-2 and p16 was investigated in 107 consecutive oro-hypopharyngeal squamous cell carcinoma cases. Molecular interrelationship and correlations with clinicopathological parameters and survival were computed.

AQP1 was expressed exclusively by a subgroup of basaloid-like squamous cell carcinomas. AQP5 was detected in 25.2 per cent of the samples, showing significant association with the absence of p16 and Bcl-2 (p = 0.018; p = 0.010). In multivariate analysis, overexpression of p16 was significantly correlated with favourable overall survival (p = 0.014).

AQP5 defined a subset of patients with Bcl-2-negative and p16-negative tumours with a poor clinical outcome. AQP1 was found to be a marker of a subgroup of aggressive basaloid-like squamous cell carcinomas. These findings suggest that AQP1 and AQP5 are interesting candidates for further studies on risk group classification and personalised treatment of oro-hypopharyngeal squamous cell carcinomas.