What are secondary cancers? How do they arise?

Secondary cancers can arise in two ways: a new primary cancer (different from the original cancer) that develops after the treatment of the first type of cancer, or tumors that arise from the migration of cancer cells into a different location (also called metastatic tumors), through a process known as metastasis of a primary cancer. This could be done through a series of steps:

1. growing into nearby normal tissue
2. entering nearby lymph nodes or blood vessels
3. traveling to other parts of the body using our blood vessels and/or lymphatic vessels
4. stopping in blood vessels at another location far away from the primary tumor and moving into the surrounding tissue
5. growing in this tissue until a tiny tumor forms
6. causing new blood vessels to grow (see more in our FAQ on angiogenesis), which creates a blood supply that allows the secondary cancer to continue growing