<p>There are three main methods of treating cancer – surgery, radiotherapy and chemotherapy – each having a specific role in the management of malignant tumours, and each of which can be used to complement the other. This article will attempt to provide an understanding of how chemotherapeutic drugs work by acting on the cell cycle, since this knowledge is fundamental to understanding the therapy that offers the best approach to treating widespread metastatic disease (Langhorne 1997).</p>