I meant that every cancer diagnosis is done by a pathologist who describes the looks of the cell/tissue and is trained to assign a cancer classification to it. This is currently changing to genetic testing where the underlying mutation (that is causing the tissue changes) is identified. AFAIK the tissue classification is still the gold standard for most cancer types, but I am positive that this will be completely replaced by the new methods. Medicine will not put the cells under a microscope anymore but into a DNA analyzer instead.