Moin, the lifespan can actually be quite long, but the canker needs constant control and treatment. You did well to cut the branches and you can easily cut out the smaller wounds that are leaking. Remember to treat them with some kind of plaster afterwards. In addition it is extremly important to desinfect the tools that where used to cut out the infected material. Canker is a very usual symptom with a lot of possible causes that lead to the bleeding. Do avoid even the smallest damages at the tree except for the cutting you need to do to stop the infections. Gruß Meyer