So there “normal” tumors and “abnormal” tumors...
Certainly. If you go to a tanning salon every day and cook yourself, then a skin melanoma is a quite normal tumor to expect. If you smoke cigarettes for 40 years, then a lung carcinoma is also a normal tumor to expect.
Now, when gay men in the 80s started developing Carposi’s sarcomas, those were abnormal tumors, since normally healthy young men with functioning immune systems don’t develop those tumors. So abnormal tumors can be a big red flag that something unusual is going on...