She went back once a year for checks for 4-5 years. It was only when she was called into see an oncologist and told an unrelated x-ray lead them to discover she had stage 4 metastatic melanoma (brain, liver, spine, femur, lungs and i’m sure i’m forgetting something) that we found out that they’d only been giving her visual checkups each year, no PET scans or anything else. The oncologist was shocked that the checks were so basic, mom didn’t know she was supposed to have anything else and she was dead in about 8 weeks.
We were told that the form of melanoma only came back like that in 1% of patients and usually simple visual checkups were enough. I have no idea how true that is.