after treatments are completed

[spouse]

my wife was diagonsed with cancer over a year ago with a pleural effusion and an unknown primary. she had 6 treatments of taxol/carbo, a complete response was achieved after the first 3 by a cat scan. after an additional 3 treatments she had a complete hysterectomy which revealed the primary in her overies, small volume residual disease. she then had 9 weekly infusions of taxol as insurance treatments. after the treatments a cat scan came back normal and the last 3 months her blood tests have been fine -CA125 in the low teens. what is the standard for blood test frequency - monthly for 6 months, a year or longer. if her blood levels stay flat for 6 months does that give better chances of a longer remission and is there any type of vitamin supplement that she can take that will boost her immune system to help fight off a reoccurance. the doctors all say just eat well, but i read a boatload of info on the internet about immune boosting meds and mega vitamin supplements etc. thanks for your help.