(B-023) A novel salivary-based companion diagnostic device for early detection and monitoring of HER-2+ breast cancer patients in resource-limited settings

Background: The link between a mutation in the erbB2 gene and cancer has led to significant interest in diagnostics and treatment. HER2-positive breast cancer, caused by gene amplification, affects about 20-30% of patients and is associated with poorer prognosis, higher recurrence rates, and lower chemotherapy response. Determining HER2 status is essential in breast cancer diagnosis, but conventional methods like immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) are often inaccessible in resource-limited settings. Their sample collection techniques are pretty invasive and can induce anxiety associated with screening. This challenge underscores the need for non-invasive and accessible diagnostic alternatives

Objectives: To design and develop a point-of-care salivary-based companion diagnostic device for early detection and monitoring of HER2 breast cancer patients in resource-limited settings

Methods: This study uses an experimental approach consisting of three main phases: biomarker validation, sensor functionalization, and sensor validation. The following steps involve attaching a probe to a gold working electrode to functionalize it with anti-erbB2 molecules from trastuzumab. This process utilizes the electrical double layer concept, where the antibody-antigen binding is expected to produce a response to HER2 molecules in saliva samples. The sensor should meet the basic requirements for a companion diagnostic, including sensitivity, specificity, predictive values, and likelihood ratios

Results: Preliminary findings suggest that salivary HER2 is a viable diagnostic biomarker using the ELISA technique, achieving a TPR/FPR ratio of 6:1, which meets the minimum performance criteria.

Conclusions: Such a device would reduce the cost of breast cancer screening for women in underserved areas. The non-invasive approach will effectively reduce anxiety around breast cancer screening, significantly improving screening rates and ensuring better epidemiological outcomes.