ABSTRACT
Cancer is not one disease, but a multitude of different diseases. Cancers can arise in different organs and cell types, and have different visual aspects under the microscope. They have different epidemiological risk factors, different patterns of progression, they respond to different treatments, and are associated to different risks of relapse∗. In a sense, each cancer is unique since it is intimately associated to the unique genetic background and somatic evolution of each individual (see Section 2.1).
