What Is the Incidence of Occult Metastasis in Patients with Stage N₀ Cancers of the Head and Neck?

There is a large body of evidence in the European and US literature which argues forcefully that the presence of metastatic deposits within cervical lymph nodes is the single most significant independent adverse prognostic factor in patients with squamous-cell carcinomas of the head and neck. When all head and neck cancers are considered, ipsilateral lymph node metastases appear to decrease patient survival by as much as 50%; moreover, the presence of contralateral or bilateral cervical metastases reduces prognosis by an additional 50%. Patients with cervical metastases seem to be more likely to develop both distant metastases and local recurrences at the primary site.