I have lung cancer Vietnam vet. I have been treated and will be in remisssion; however, I will have to be on oxygen the rest of my life. I have not received my 100% yet but I understand that when it goes to remission, I will probably get nothing. I can't get a job like I am and I employed before.
An agent orange presumptive lung cancer is rated at 100% while the cancer is active. Once treatment happens, the residual effects of any treatment will be the permanent rating. If you are on home oxygen the rating will be 100% for as long as you're on oxygen. The regulations explain that here.