In this study, we evaluated the extent of inappropriate tumor marker (TM) ordering in a secondary care setting, approximately 6 years after the introduction of local guidelines, and we identified the main factors potentially influencing clinicians when performing an inappropriate TM request.
For this purpose, we regularly checked all requests containing more than two TMs. During the 21-month audit, the rate of rejected requests amounted to 3.6%. Several of those were performed for diagnostic purposes. The most frequent and inappropriately requested TMs were carcinoembryonic antigen and carbohydrate antigen 19.9.
The inappropriateness of requests appeared to be linked to the need for more education and knowledge on their clinical applicability and limitations. The clinical motivation was generally associated with patients displaying nonspecific signs/symptoms (ie, weight loss with worsening general conditions), having an incidentally positive result to some recently performed TM tests, or being tested by a TM to avoid more expensive diagnostic imaging procedures.
Our data show that real-time control and management of inappropriate requests by laboratory professionals may be relevant to increase the clinical efficacy of TM testing and useful in perspective to drive the introduction of new validated biomarkers.