Thanks for posting your query.
It goes with the type of cancer which I mean is histological type and stage at which it was diagnosed.
Usually staging considers many factors and treatment is initiated based on staging.
Since you are disease free since 7 years you need to go for follow up as suggested by your doctor.
Since there is an entity called micro metastasis which means the tumor
which can spread even though the primary has been removed and can occur at any time.
So regular follow up is mandatory.
Hope I have answered your query.
Wishing you good health.