Towards evidence-based use of serum tumour marker requests: an audit of use in a tertiary hospital.
BACKGROUND
Serum tumour markers (TM) are often measured in hospital patients. The reasons for their use and their benefits with regards to earlier cancer diagnosis and patient management are not known.


OBJECTIVE
To identify the patterns of TM use in a tertiary hospital and to determine the usefulness and appropriateness of requests in this setting.


METHODS
A cross-sectional, retrospective study of TM ordered over a 3-month period was conducted. Data were obtained from patient records. CA-125, CA 15-3, CA 19-9, carcinoembryonic antigen (CEA), and alpha-fetoprotein (AFP) were studied. Prostate specific antigen was not separately investigated. The reasons for ordering, usefulness and appropriateness of use were defined prior to analysis.


RESULTS
A total of 476 TM was ordered in 373 patients. One hundred and six (22%) of all results were abnormal by laboratory criteria. AFP was the most popular test ordered. Forty-seven per cent of patients had no cancer diagnosis. Oncological units (ONC) ordered 27% of tests. The most popular reasons for TM ordering were for screening (36%) followed by diagnostic aid (19%). ONC units ordered TM mainly for monitoring disease status, as opposed to non-ONC units who ordered TM usually for diagnostic aid. TM were deemed appropriately ordered in 69% of cases. Twenty-nine per cent of TM were helpful in patient management. Only four results (<1%) aided in diagnosis.


CONCLUSIONS
The reasons and appropriateness of TM use varied depending on the specialization of the requesting clinician. The current serum TM are most useful as aids in cancer patients, rather than for diagnosis (P <0.0001). Apart from AFP, these TM seem to have limited use in the general medical, non-oncological patients. Guidelines for their use in this setting are needed.
Loi
S
S
Department of Medical Oncology and Haematology, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia. sherene.loi@bordet.be
Haydon
A M M
AM
Shapiro
J
J
Schwarz
M A
MA
Schneider
H G
HG
D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood*; D002272:Carcinoembryonic Antigen / Q000097:blood; D019963:Clinical Chemistry Tests / Q000706:statistics & numerical data; D003430:Cross-Sectional Studies; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D012189:Retrospective Studies; D000509:alpha-Fetoproteins / Q000032:analysis
D015295:Antigens, Tumor-Associated, Carbohydrate; D014408:Biomarkers, Tumor; D002272:Carcinoembryonic Antigen; D000509:alpha-Fetoproteins