Q.Spread of cancerous cells to distant sites is termed as (A) Metastasis (B) Oncogenes (C) Proto-oncogenes (D) Malignant neoplasm

Tumour immunology studies how the immune system interacts with cancer. A tumour (neoplasm) is a mass of cells whose growth has escaped normal control; when it invades healthy tissue it is called cancer, and cells that spread to distant sites to form new growths cause metastasis. Tumours may be benign (indefinite growth without invasion) or malignant (invasive, migratory growth). The underlying defect is loss of contact inhibition, the normal brake on cell division once cells touch neighbours. Malignant transformation often changes a cell's surface antigens, which can provoke both humoral and cell-mediated immune responses, though cancer cells frequently evade detection because they are altered self cells rather than truly foreign. Immunological surveillance is the theory that the immune system contin …