Evaluation of the new Elecsys SCC assay: comparison with the Kryptor SCC assay

Method Comparison and Clinical Performance of Breast Cancer Tumor Markers on Novel Multiplex Immunoassay and Automatized LOCI Technology Platforms

Tumor marker determinations are valuable tools for the guidance of breast cancer patients during the course of disease. They are assessed on diverse analytical platforms that may be associated with differences according to the methods applied and the clinical performance. To investigate the method dependency and clinical significance of breast cancer protein tumor markers, CEA, CA 15-3, CA 125, CA 19-9 and AFP were measured in a total of 154 biobanked samples from 77 patients with breast cancer, 10 with DCIS, 31 with benign breast diseases and 36 healthy controls using a Millipore multiplex biomarker panel (MP) and an automized version of the routinely used Vista LOCI technology. The markers were compared between methods and investigated for diagnostic performance. CEA, CA 15-3 and AFP showed good correlations between both platforms with correlation coefficients of R = 0.85, 0.85 and 0.92, respectively, in all samples, but similarly also in the various subgroups. CA 125 and CA 19-9 showed only moderate correlations (R = 0.71 and 0.56, respectively). Absolute values were significantly higher for CEA, CA 15-3, CA 125 and AFP in the Vista LOCI as compared with the MP method and vice versa for CA 19-9. The diagnostic performance for discrimination of breast cancer from healthy controls was similar for both methods with AUCs in ROC curves for CEA (MP 0.81, 95% CI 0.72-0.91; LOCI 0.81; 95% CI 0.72-0.91) and CA-15-3 (MP 0.75, 95% CI 0.65-0.86; LOCI 0.67, 95% CI 0.54-0.79). Similar results were obtained for the comparison of breast cancer with benign breast diseases regarding CEA (AUC MP 0.62, 95% CI 0.51-0.73; LOCI 0.64, 95% CI 0.53-0.74) and CA-15-3 (MP 0.70, 95% CI 0.6-0.81; LOCI 0.66, 95% CI 0.54-0.77). Both platforms show moderate to good method comparability for tumor markers with similar clinical performance. However, absolute levels in individual patients should be interpreted with care.

Performance characteristics of the BRAHMS KRYPTOR automated squamous cell carcinoma antigen assay

BACKGROUND

Squamous cell carcinoma antigen (SCCA) is a glycoprotein biomarker for squamous cell carcinoma (SCC). SCCA elevations have also been noted in other conditions. The purpose of this study was to evaluate the analytical and clinical performance of an automated SCCA homogenous immunofluorescent assay (BRAHMS KRYPTOR).

METHODS

Reference intervals were determined using 119 samples from healthy donors. To assess clinical performance, samples were collected from patients with cervical (n = 12), head and neck (n = 23), lung (n = 14), or cutaneous (n = 11) SCC in addition to hepatocellular carcinoma, psoriasis, or atopic dermatitis.

RESULTS

Upper 95th percentile sex-specific reference intervals were 2.00 μg/L for males and 1.67 μg/L for females. Intra- and inter-assay CVs were less than 5%. Comparison of the BRAHMS KRYPTOR to an ELISA SCCA immunoassay exhibited a correlation coefficient of 0.8809. The mean sensitivity for all SCC positive patients was 23.3%. With the exception of psoriasis (58.6%) specificity exceeded 95% for the non-SCC populations.

CONCLUSION

The BRAHMS KRYPTOR SCCA assay showed good analytical performance and acceptable overall clinical specificity. Consistent with previous studies, the sensitivity of SCCA for SCC was low. In the absence of other robust circulating markers, SCCA remains an imperfect yet useful tool in the evaluation of SCC.

Comparison Between a Manual Squamous Cell Carcinoma Antigen Assay and an Automated Assay in a Clinical Setting

Objective

To compare a manual squamous cell carcinoma antigen (SCCA) assay and an automated SCCA assay in a clinical setting.

Methods

We included, in this study, a total of 158 specimens that had been tested using the manual SCCA assay. The CanAg SCC EIA assay and the Elecsys SCC were compared for their clinical settings.

Results

Within-run and between-day coefficients of variation (CVs, %) were lower than 3%. Comparison of the manual and automated SCCA assays yielded good correlation. The correlation coefficient (R2) between the CanAg SCC EIA and Elecsys SCC assay results was 0.989 (P <.001) and the overall concordance rate was 94.3%.

Conclusions

We report that the Elecsys SCC automated SCCA assay yielded performance comparable to that of the manual SCCA assay: the automated assay reduced the number of manual steps and test turnaround time.