Critical Immune Checkpoints Linked with NK and T Cells for Overall Survival of Breast Cancer Subtypes

Breast cancer is the second leading cause of cancer death in women. Since cancer disrupts immune checkpoints to suppress the anti-tumor response, we assessed immune checkpoint signatures linked with NK and T cells in breast cancer including triple-negative breast cancer (TNBC) subtypes. Furthermore, critical immune checkpoints related to overall survival were identified using the in-silico and comparative analysis. Immune checkpoint signatures were breast cancer subtype-specific, showing differential signature in each subtype. High levels of immune checkpoints were related to overall survival in some breast cancer subtypes. The differential overall survival rates of breast cancer subtypes may be due to the final net balance of total immune checkpoints by exerting either inhibitory or stimulatory interaction with immune cells. Critical immune checkpoints for poor overall survival of breast cancer subtypes are as follows: UL16 binding protein 2 (ULBP2) in both basal-like breast cancers and basal-like 2 TNBC subtype; V-set domain containing T cell activation inhibitor 1 (VTCN1) in immunomodulatory TNBC subtype. In conclusion, specific immune checkpoints may differentially influence overall survival in a breast cancer subtype-specific manner.