Limitations
In this cohort, only two patients had a bilateral ND, with both patients having both necks staged as cN+ve (and therefore, no occult nodes found). Other studies have described frequencies of nodes in contralateral dissections as well as ipsilateral, although with insufficient frequencies of occult nodes to justify routine contralateral ND in all cases.4, 10, 12, 13, 17 In patients who are managed with primary surgery to the contralateral neck, further analytical work is required to demonstrate the pattern of contralateral lymph node metastasis.
Lastly, despite the high negative predictive value of p16-ve protein expression for the absence of HPV, Royal College of Pathology advice recommends in-situ hybridisation of all p16+ve specimens to confirm HPV, which was not routinely available at our institution during the study period done. We estimate that 4% of patients excluded from the analysis on the basis of having p16-ve disease may therefore have been eligible for inclusion; exact data is, however, not known.18