ERRORS IN MITOSIS
Errors in the control of mitosis may cause cancer. All cells have genes that control the timing and number of mitosis. Sometimes mutation occurs in such genes and cells continue to divide. It result in growth of abnormal cells tumors. As long as these tumors remain in their original location, they are called benign tumors. But if they invade other tissue, they are called malignant (cancerous) tumors and their cells are called cancer cells. Such tumors scan send cancer cell to other parts in body where new tumors may form. This phenomenons is called metastasis (spreading of disease).
All data collected from my book of Science.