Stefano,
Welcome, we are sorry that you have a reason (bladder cancer) to be here but, glad you found us. First, did you have any follow up treatment such as BCG or other agent? That is very important on the type you describe to fight it. As far as your doctor's comment on scar tissue in the lung. I would presume they are correct as they are supposed to be "experts". At the same time if you are allowed a second opinion, for peace of mind I'd get one.