Abstract
We studied the diagnostic accuracy of carcinoembryonic antigen (CEA) and cancer antigen 15.3 (CA 15.3) in detecting breast cancer recurrence. Biomarker follow-up determinations, made over 900 patients, were related to local–regional or distant recurrence using statistical models for longitudinal data. The diagnostic accuracy was quantified in terms of sensitivity, specificity and Youden index. The biomarkers were poorly predictive of local–regional recurrence. As for distant recurrence, the best diagnostic accuracy was obtained considering the two biomarkers jointly and combining two positivity criteria: a value above the normal limit or a difference between two consecutive measurements greater than the critical difference for at least one biomarker. A third criterion, based on within-patient comparison between follow-up determinations and a baseline, failed to improve the above result. CEA and CA 15.3 might play a role in patient monitoring during follow-up for the search of distant recurrence.
Acknowledgements
The authors wish to acknowledge ‘ABO Project 2010’ and ‘ASSOCIAZIONE ABO per l’applicazione delle biotecnologie in oncologia’ for financial support.
Declaration of interest: The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.