Objectives: This study assessed the level of appropriateness of tumor marker requests in a teaching hospital and estimated the financial cost associated with inappropriate use. Methods: A retrospective review of patients’ electronic records was conducted over a 3-year period (2015–2017) for tumor marker requests, including carcinoembryonic antigen, alpha-fetoprotein, cancer antigen (CA)15-3, CA125, CA19-9, and total and free prostate-specific antigen (PSA and fPSA), along with the associated clinical data that motivated the requests. Inappropriate use was defined as tumor marker requests without any relevant clinical picture. Costs due to inappropriate tumor marker requests were estimated based on the unit costs applied in the institution. Results: A total of 7128 patients had at least one tumor marker request between 2015 and 2017. The clinical picture that motivated tumor marker requests was absent in 71.5%, while 12.9% of the requests were associated with a malignancy. The most frequent prescribing pattern was total prostate-specific antigen alone (2128; 29.9%), followed by alpha-fetoprotein alone (1185; 16.6%), and carcinoembryonic antigen alone (506; 7.1%). Year-over-year analysis revealed an increasing tendency in requesting carcinoembryonic antigen and CA15-3. The rate of inappropriate use varied by tumor marker and ranged between 56.4% for fPSA and 86.8% for total prostate-specific antigen. The overall costs due to inappropriate tumor marker requests were estimated at $2,785,493 over the 3 years, representing an average of $0.93 million per year. Conclusion: Inappropriate use of tumor marker requests is a major issue regarding its high prevalence and the considerable associated costs. The role of laboratories in the management of tumor marker requests should be emphasized.
Alpha-fetoprotein (AFP) as tumor marker in a patient with urothelial cancer with exceptional response to anti-PD-1 therapy and an escape lesion mimic
