Cross-species insights into CEACAM1 autoantibodies as diagnostic biomarkers for mammary cancer.

Abstract

Identifying reliable serological biomarkers for cancer is crucial for improving diagnosis, prognosis, and treatment outcomes. This study evaluates carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) autoantibodies as potential biomarkers for canine mammary tumours (CMTs) and human breast cancer (HBC). Given CEACAM1's role in immune regulation and tumour biology, we hypothesised that CEACAM1 autoantibodies could serve as diagnostic and prognostic markers. We assessed CEACAM1 autoantibody levels in sera from dogs with mammary tumours and humans with breast cancer. The immunodominant region of CEACAM1 was cloned and expressed in E. coli, and a recombinant CEACAM1 protein-based indirect ELISA was developed. The assay demonstrated high sensitivity and specificity, with an area under the curve (AUC) of 0.9230 for CMTs and 0.9068 for HBC. Validation using dot blot assays confirmed the ELISA specificity. To assess their potential for early detection, sequential serum samples from chemically induced mammary tumours in rats were analyzed. CEACAM1 autoantibodies were detectable before clinical tumour manifestation, highlighting their promise as early diagnostic markers. However, larger independent cohorts are needed for validation. In conclusion, this study demonstrates the potential of CEACAM1 autoantibodies as biomarkers for detecting mammary tumours in dogs and suggests their applicability in human breast cancer diagnostics. Integrating CEACAM1 autoantibody levels into diagnostic protocols could enhance cancer detection. Further research is warranted to establish their clinical utility in both veterinary and human oncology.