Combined therapy of cancer (e.g., breast cancer such as triple negative breast cancer) involving a cyclophosphamide compound and natural killer (NK) cells. Also provided herein are methods for inducing immune memory and/or reducing the risk of tumor recurrence using the combined therapy of a cyclophosphamide compound and NK cells.一種癌症(如乳癌,例如三陰性乳癌)組合療法,包含環磷醯胺(CTX)化合物及自然殺手(NK)細胞。本文亦提供使用環磷醯胺化合物及NK細胞組合療法,用以誘發免疫記憶及/或降低腫瘤復發風險的方法。