Tumor-associated antigen (TAA) (TAA)

Tumor-associated antigens (TAAs), often referred to as broad tumor antigens, are a diverse class of molecules that are expressed across various types of cancer but have limited expression in normal tissues (National Cancer Institute, 2023). These antigens include overexpressed self-proteins (e.g., HER2, MUC1), differentiation antigens, and cancer-testis antigens (e.g., NY-ESO-1), which are typically restricted to germ cells but re-expressed in malignancies (Gnjatic et al., 2006). Because these antigens are shared among many patients, they are primary targets for "off-the-shelf" immunotherapies, such as monoclonal antibodies, cancer vaccines, and chimeric antigen receptor (CAR) T-cell therapies (Vigneron, 2015). The biological function of these antigens varies; many are involved in promoting cell proliferation, inhibiting apoptosis, or facilitating signal transduction, which provides the tumor with a survival advantage. However, a significant therapeutic challenge is "on-target, off-tumor" toxicity, which occurs when the target antigen is also expressed at low levels in healthy, vital organs (Abbott et al., 2020). Additionally, tumors may develop resistance through antigen escape, where the expression of the target antigen is downregulated or lost under therapeutic pressure (Majzner & Mackall, 2018). Despite these challenges, targeting broad tumor antigens remains a cornerstone of modern oncology, offering the potential to treat large patient populations with standardized therapeutic agents.

Other names

Broad tumor antigensShared tumor antigensPan-cancer antigensUniversal tumor antigensTumor-associated proteins

Targeting of shared tumor-associated antigens via monoclonal antibodies, vaccines, or adoptive T-cell therapies to induce immune-mediated tumor cell lysis.