CEACAM5: An Emerging Biomarker

CEACAMs, carcinoembryonic antigen-related cell adhesion molecules, are part of the immunoglobulin superfamily of proteins.

There are 12 CEACAM proteins that impact cell function, including adhesion, differentiation, proliferation, and survival.

One member of the CEACAM family, CEACAM5, is currently being explored as a potential biomarker, as it may play a role in tumor progression and metastases.

CEACAM5 is expressed at low levels on the interior surface of normal epithelial tissue and functions to protect luminal organs from microbial infection.

However, in some tumors like non-squamous non-small cell lung cancer, colorectal cancer, gastric cancer, pancreatic cancer, and breast cancer, there are higher levels of CEACAM5 expression.

Additionally, high CEACAM5 expression may cause a loss of polarity, which is also a sign of tumor progression and cell cycle abnormalities.

Therefore, CEACAM5 is currently being explored as a potential biomarker, as it may play a role in tumor progression and metastases.

CEACAM5 has been shown to have a lower expression in normal lung tissue, and higher expression in non-squamous non-small cell lung cancer.

In early investigational studies, up to 25% of non-squamous non-small cell lung cancer patients had evidence of high CEACAM5 expression.

CEACAM5 expression can be tested with tissue-based immunohistochemistry, using new or archival biopsy tissue.

The different levels of CEACAM5 expression between normal and tumor tissue may provide a potential target for cancer therapies.

Let's take a closer look at the cellular-based protein, CEACAM5. CEACAM5 is currently being explored as a predictive biomarker in nonsquamous non–small cell lung cancer due to its high differential expression and its prevalence. When looking at protein expression, CEACAM5 is highly expressed in tumor tissue, but it's virtually undetectable in normal lung tissue. This high differential expression in lung cancer cells indicates that CEACAM5 has the potential to become a target in advanced nonsquamous non–small cell lung cancer.

Meanwhile, early studies show that approximately 1 in 4 advanced nonsquamous non–small cell lung cancer patients has a high expression of CEACAM5. High expression of CEACAM5 in advanced nonsquamous non–small cell lung cancer is defined as expression of at least 2+ intensity in at least 50% of tumor cells. Along with CEACAM5, TROP2 and cMET have emerged as potential biomarkers in NSCLC. Although more work needs to be done to confirm the possible relationship between CEACAM5 and other emerging biomarkers like TROP2 and cMET, a recent tissue mRNA sequencing study done on 537 lung adenocarcinoma samples reported inverse correlation of CEACAM5 and TROP2 and appeared to be nearly mutually exclusive biomarkers. Thus, based on these findings about its high differential expression and prevalence in advanced nonsquamous non–small cell lung cancer, there is reason to believe that CEACAM5 could become a useful predictive tool for lung cancer treaters and their patients. Thanks for taking the time to learn more about CEACAM5. t