Natural Killer (NK) Cells in Tumor Immunity: Limitations and Therapeutic Potential with a Focus on Nasopharyngeal Carcinoma and Comparison with T-Cell-Based Therapies.

Natural killer (NK) cells are increasingly recognized as a complementary platform to T-cell-based cancer immunotherapies. Their innate, MHC-unrestricted recognition, capacity to mediate antibody-dependent cellular cytotoxicity (ADCC) and comparatively favorable toxicity profile have given rise to a broad therapeutic pipeline that includes cytokine-supported regimens, adoptive NK products, bispecific and trispecific NK engagers, and chimeric antigen receptor (CAR)-engineered NK cells. Clinical data, particularly in hematologic malignancies, show that NK-cell-based strategies can be safe and biologically active, although limited persistence, suboptimal trafficking and immune escape remain key challenges. Nasopharyngeal carcinoma (NPC), an Epstein-Barr virus (EBV)-driven epithelial cancer, illustrates how a tumor microenvironment (TME) can simultaneously impair NK function and create specific vulnerabilities that NK-focused therapies can exploit. This review summarizes NK biology and current therapeutic platforms, analyzes major limitations, highlights the specific context of NK-cell-based strategies in NPC and compares NK- and T-cell-based therapies with an emphasis on clinical translation.