Screening tests to evaluate distant metastases in head and neck cancer.

Investigation for distant metastases is part of the staging process of a primary tumor or recurrent disease before treatment. The lung is the most frequent site followed by bone and liver. Advanced stage and cervical metastases are the most important predictors of metastases. Almost all distant metastases are associated with lung metastases. Computed tomography scan of the chest is the single most effective investigation. The value of routine screening tests is questionable and merits further investigation.