tumorspecific

Tumor-specific refers to features, antigens, or targets that are largely restricted to tumor cells and are absent or minimal in normal tissues. In practice, the term is used for antigens, mutations, pathways, or imaging and therapeutic targets that allow discrimination between malignant and healthy cells. A key distinction is between tumor-specific antigens (TSAs) and tumor-associated antigens (TAAs); TSAs include mutated neoantigens arising from somatic mutations, and viral antigens in cancers caused by oncogenic viruses. TAAs can be expressed in some normal tissues, limiting their specificity and increasing the risk of on-target off-tumor effects.

Identification of TSAs relies on tumor sequencing, bioinformatic prediction of peptide-MHC binding, and validation of antigen processing and presentation. This enables personalized approaches such as neoantigen vaccines and adoptive T cell therapies, including T cell receptor–engineered T cells that recognize patient-specific neoantigens, and, in some contexts, CAR T cells directed at surface tumor-specific proteins. Tumor specificity is also sought in diagnostic imaging and targeted therapies, using ligands or antibodies that preferentially accumulate in tumor tissue.

Clinical rationale centers on increasing treatment efficacy while reducing damage to normal tissues. However, tumor heterogeneity, clonal evolution, and immune escape pose challenges; some targets may be present only in subsets of tumor cells or may be downregulated. Ongoing research aims to expand the catalog of TSAs, improve prediction and validation methods, and combine tumor-specific strategies with other treatments to overcome resistance. In sum, tumor-specific targets hold promise for precision oncology but require careful assessment of specificity, safety, and tumor biology.