Cancer is created when cell multiplication becomes uncontrolled and clumps together, which is also considered by DNA genetic changes.
In DNA sometimes the genes are turned into oncogenes which are not deactivatable and are factors of strong cell growth.
Metastasizing:
Metastasis in prostate, metastasis is the spread of cancer cells from one organ to another. In the membrane of the prostate, the cells start to overgrow and break the natural barrier. As it breaks the natural barrier cells break through the prostate and freely move through the organ spreading cancer to other organs. This is one type, another type is when the cancer cells attack the lymph vessels and spread into the lymph nodes, this is why surgeons when removing the cancer also remove the lymph nodes to check if there is cancer.
Prostate metastasis cancer usually spreads to other organs like the liver, lungs, and brain by getting inside the blood vessels the circulatory system helps the cancer to spread. Doctors usually take blood samples to calculate the amount of circulation of cancer cells in the vessel, which is still in progress as it is not spread worldwide.
Local invasion:
In this process the tumor breaks through the membrane and enters the blood vessel, it replaces the membrane so no confusion is created. It breaks the membrane with the help of MMPs, MMPs are a product when a certain signal reaches the membrane of the tumor which sends the signal to the nucleus to make the production of MMPs, which then break the membrane near and lets the tumor cells to pass through.