To begin understanding metastatic cancer, it’s important to have a general understanding of what cancer is. There are many different types of cancer, and some are more prone to metastasizing. Cancer forms in the cells, which are the building blocks of the body. If the DNA of a cell is damaged, it may cause a cell to multiply uncontrollably. By producing new cells, the cell passes on its damaged DNA, resulting in further uncontrolled growth and potentially forming a cancerous tumor. Not all tumors are cancerous, and not all cancers form solid tumors, such as most cases of leukemia. All varieties are wrapped up under the umbrella term “cancer,” but each type is different and may require a separate approach to treatment. For example, melanoma, a particularly aggressive form of skin cancer, and prostate cancer, cancer of the prostate gland, both have a higher risk of spreading throughout the body, or metastasizing.