Wiktionary
immunosurveillance
n. (context immunology English) The continuous monitoring process of the immune system whereby abnormal cells are recognized and destroyed
Wikipedia
Immunosurveillance
Cancer immunosurveillance is a process by which an organism's immune system recognizes transformed cells in order to inhibit the growth of neoplastic tissue. It comprises the first phase of immunoediting and is also known as the elimination phase.