Can you have cancer and not know it?!

Can you have cancer and not know it?

i m curious how do people know they have cancer and why some dont go to the doctor right away while its easy to cure?

I am a lymphoma stage 4 patient and been knowingly living with this now for 4 yrs with no treatment. they said i have had this for years and don't now why i am still alive . The only way they new i had it was with a bone & bone marrow biopsy. one Dr didn't think there was any thing wrong and refused to do the biopsy. the blood tests and CT scans still to this day shows nothing. so yes you can have cancer and not know it.