Tissue ELISA and Serum Amperometric Magnetoimmunosensor of ECD-HER2 In Stratifying Subtyping of Egyptian Woman Breast Cancers

Background: HER2 status is an important diagnostic and prognostic marker in breast cancers (BCs). Yet the applicability of HER2 extracellular domain (ECD) amperometric magnetoimmunosensor on patients’ samples is not tested.

Methods: Blood and tissues collected from 72 females (20 controls, five recurrent breast tumours, and 47 BCs). Tissue (tHER2) and serum HER2 (sHER2) detected by ELISA and the amperometric magnetoimmunosensor (AM) and their levels correlated to the clinicopathological parameters, and serum CA15-3 (sCA15-3).

Results: tHER2 (ELISA) and sCA15-3 significantly differed among the studied groups. tHER2 (ELISA) decreased significantly with higher BMI in HER2²⁺ group. tHER2 and sHER2 (AM) correlated significantly in HER2³⁺ group. tHER2 (ELISA) differed significantly among BCs molecular subtypes. Both tHER2 and sHER2 (ELISA) correlated significantly in HER2 molecular subgroup. sHER2 (AM) showed high significant sensitivity and specificity in differentiating TN from luminal A at > 9.26 ng/ml and HER2 at 9.6 ng/ml. However, at > 1.67 ng/ml, tHER2 (ELISA) stratified significantly between BCs molecular and HER2 subgroups.

Conclusions: In conclusion, tissue ELISA and serum AM provided useful quantitative measurements for HER2 in various BC subtypes (at cut off values lower than that approved by FDA) and would complement the current IHC and ISHs techniques.