Therapeutic potential of tertiary lymphoid structures in breast cancer (Review)

Tertiary lymphoid structures (TLS) are organized immune aggregates within the tumor microenvironment that are associated with improved prognosis and immunotherapy response in breast cancer, yet their functional duality and therapeutic potential require further clarification. The present review comprehensively summarizes current knowledge on TLS in breast cancer, focusing on their molecular mechanisms of formation and maturation, multifaceted functions in anti‑tumor immunity, established prognostic importance and emerging strategies for therapeutic targeting. The present study highlights that mature and functional TLS are key mediators of adaptive anti‑tumor immunity, whereas immature TLS may have opposing effects. Their presence and characteristics hold strong prognostic value and can predict response to immune checkpoint inhibitors. Consequently, therapeutic strategies aimed at inducing or enhancing TLS represent a promising direction for breast cancer immunotherapy. However, further research is needed to elucidate the precise regulatory networks and translate TLS‑focused strategies into clinical practice.