Nope, the worst cancer of all is the one you have.
For me, it is Chronic Lymphocytic Lymphoma and for my mom, it was liver cancer.
For me the worst cancer was glioblastoma multiforme, in my little sister. It basically dissolves the brain.
I have CLL as well, since the ‘90s. For me it’s been annoying, but actually somewhat the opposite of scary. My greatest fear prior to CLL was living too long, becoming a invalid and burdening others for years, like so many others in my family. Not likely now.