Clinicopathological features associated with secondary cervical lymph node metastases (SLM) of squamous cell carcinomas of the head and neck were investigated. SLM were found in 27 (17. 2%) of 157 TXNO head and neck carcinoma cases from November 1975 to June 1991. The most common primary site was the tongue (21 cases), and approximately 80% of SLM occurred within one year after primary treatment; this period was therefore felt to be the most appropriate for follow-up. The five-year cumulative survival rate for SLM cases was 40. 7%. Reasons for decreased survival in these cases included the following:
1. Tumors in metastatic nodes were histologically more invasive than those in the primary site.
2. Multiple metastases to cervical lymph nodes were present.
3. Spreading to multiple levels of the cervical lymph node chains had occurred.
4. Extra-nodal spread and metastases to distant cervical levels were observed in many cases.
Extra-nodal spread, the number of positive nodes and the level of positive nodes were the most important prognostic factors in SLM cases. No factor predicted which patients were more likely to have SLM in tongue carcinoma. Thus, there were no absolute indications for elective neck dissection (END). END should, however, be considered in carcinomas showing diffuse invasive (grade 4C and 4D) or endophytic growth types or those cases where invasion of the floor of the mouth, retromolar region and base of the tongue is present.