Head activator as a potential serum marker for brain tumour analysis.

Some human brain tumours, especially those derived from neuroectodermal or neural crest cells, contain elevated levels of head activator (HA). Such tumours release HA into the general circulation resulting in up to 1000-fold higher HA serum concentrations. The diagnostic value for brain tumour analysis was studied by measuring HA serum levels before and after human brain tumour surgery. It was found that complete removal of the tumour resulted in normal HA serum levels postsurgically. Incomplete resection was accompanied by a marked decrease, but not a return to normal HA levels. Surgery as such did not influence HA serum levels, since no change was observed pre- and postsurgically in patients with normal HA serum levels. This confirms the potential usefulness of HA as a serum marker to monitor brain tumour progression, successful tumour removal and relapse.