How Does A tumor grow?

Cancer starts when cells in our body divide out of control. If these cells stayed in one place, then the tumor would usually be relatively easy to treat by surgery. But cancer can grow and spread around the body, making treatment more difficult.Some tumors are slow growing, some are extremely aggressive and fast growing. It depends on their histology, origin site, hormonal sensitivity, and many unknown factors. First of all there are two main kind of tumors: benign and malign. The second type is the worst because it's not only a mass of cells which lose the capacity of auto-regulation in its growth but it shows the capacity of infiltrate and destroy the cells around. So the growth is due by the lose of regulatory system that characterize a healthy body (independence of tumoral cells from every hormone, grow factor, Dna repair system, and so on) when you get a tumor you have to value with a good doctor which is the best kind of therapy according to professionals.