Circulating markers in squamous cell carcinoma of the head and neck: a review

Biological markers of disease enhance the ability to diagnose, treat and evaluate results of therapy and are especially intriguing for their potential use in the management of malignant tumours. The serum levels of various biochemical substances have been shown to be abnormal for many cancers and are utilised in the management of affected patients. Several markers have been thoroughly investigated for potential clinical utility in head and neck carcinoma. Although no single marker has been found to be adequately sensitive and specific, combinations of markers may improve the utility for some aspects of patient management. This review highlights the literature to date in the realm of circulating markers for head and neck carcinoma. A discussion of the potential usefulness and limitations of such markers follows.