Clinical utility of tumour marker velocity of cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) in breast cancer surveillance.

BACKGROUND: Serum tumour markers, cancer antigen 15-3 (CA 15-3) and carcinoembryonic antigen (CEA) are not routinely recommended for detecting breast cancer recurrence and monitoring treatment. In this study, we aim to evaluate the diagnostic accuracy of absolute CA 15-3 and CEA levels and report on the clinical utility of tumour marker velocity in breast cancer surveillance. METHODS: 67 consecutive patients over a 15-year period (1998-2012) with available serial serum CA 15-3 and CEA measurements at recurrence were matched to a control group of patients. Tumour marker velocity was derived from the average change in consecutive tumour marker values over time, expressed in unit/year. Logistic regression analysis was performed to investigate the association between tumour characteristics, tumour marker velocity and disease recurrence. RESULTS: Using the Youden index values, the optimal cut-off values for absolute CA 15-3 and CEA corresponded to the normal assay reference range while tumour marker velocity values were derived to be 2.5U/mL/year and 1.2ng/mL/year respectively. CA 15-3 velocity > 2.5U/mL/year had the highest AUROC value of 0.85 than CEA velocity alone. When either tumour marker velocity exceeded threshold values, the sensitivity, specificity, negative predictive value and positive predictive value were 94.0%, 73.1%, 92.5%, and 77.8% respectively. In the multivariate logistic regression analysis, having both CA 15-3 and CEA velocity exceeding the cut-off values was shown to be a significant predictor for disease recurrence (p = 0.01). CONCLUSION: These findings highlighted the clinical utility of serial tumour markers measurements and its velocity in breast cancer surveillance.

Network meta-analysis of novel and conventional sentinel lymph node biopsy techniques in breast cancer.

Background: The aim of this network meta-analysis was to compare the performance of blue dye alone or in combination with radioisotope (technetium-99m, Tc) with three novel techniques for sentinel lymph node detection in breast cancer: indocyanine green fluorescence (ICG), superparamagnetic iron oxide (SPIO) nanoparticles and contrast-enhanced ultrasound imaging (CEUS). Methods: PubMed, Embase, the Cochrane Library, China Knowledge Research Integrated Database, ClinicalTrials.gov and OpenGrey databases were searched up to 31 November 2017, without language restriction. Studies that compared the detection performance of at least one of the novel methods (ICG, SPIO and CEUS) with that of traditional methods (blue dye and/or radioisotope) were included in network meta-analysis. Results: Thirty-five studies were included. Pooled risk ratios (RRs) for Tc (1·09, 95 per cent c.i. 1·04 to 1·15), ICG (1·12, 1·07 to 1·16) and SPIO (1·09, 1·01 to 1·18) showed statistically better performance in detecting sentinel lymph nodes than blue dye alone. ICG had the lowest false-negative rate, with a RR of 0·29 (0·16 to 0·54), followed by Tc (RR 0·44, 0·20 to 0·96) and SPIO (RR 0·45, 0·14 to 1·45), with blue dye alone as the reference group. Conclusion: SPIO or ICG alone are superior to blue dye alone and comparable to the standard dual-modality technique of blue dye with Tc.