Elevated tumour marker: an indication for imaging?

Abstract

Introduction: The purpose of this study was to evaluate the utility of imaging examinations in patients with elevated tumour markers when (a) the tumour marker is not validated for as a primary diagnostic test; (b) the patient had no personal history of cancer and (c) the patient had no other imaging indication.

Materials and methods: Patients without known cancer who had abnormal carcinoembryonic antigen, CA19-9, CA125 and/or CA15-3 serology over a one-year period were included. A retrospective medical record review was performed to assess the number of these cases who underwent imaging because of 'elevated tumour marker' in the absence of a clinical indication for imaging. The number and result of these imaging studies were evaluated.

Results: Eight hundred and nineteen patients were included. Of those, 25 patients (mean age: 67.8 [range 41-91] y), were imaged to evaluate: 'elevated tumour marker'. They underwent 29 imaging studies (mean [+/-standard deviation (SD)] per patient = 1.2 [+/-0.4]), and had 42 elevated tumour marker serology tests (mean [+/-SD] per patient = 1.7 [+/-0.7]). Four patients had >1 imaging test. No patient had an imaging study which diagnosed a malignancy or explained the elevated tumour marker.

Conclusion: The non-judicious use of tumour markers can prompt further unnecessary investigations including imaging. In this study, there was no positive diagnostic yield for imaging performed for investigation of 'elevated tumour marker'. 'Elevated tumour marker', in the absence of a known underlying malignancy, should not be considered an independent indication for imaging.