Pre-lymphoma???

Guy at work has really high white-blood cell count(maybe other test results that I don't know about) and Dr. has told him he is targeted to get Lymphoma in the future and that there is nothing one can do to prevent it/treat it now until it actually becomes the disease. Has anyone ever heard of this??? I am sure there is something he could be doing to prevent it from developing, does anyone know what??? Thanx for any posts. Tweet