Ovarian cancer is not the typical cancer, it is actually a healing phase rebuilding of a necrosis of the ovary. When the cancer is discovered the growth is already healing the necrosis.
I would say the diet didn't cure the cancer, its that the oncologist didn't kill the patient and she healed naturally.
If the emotional conflict regarding the tumorous growth has been only partially resolved the tumor may continue to grow and create dangerous complications.
Cause and effect does not always correlate with our empirical physical observations. I recall a man that had a heart attack while eating ham on rye. The neighborhood people, (mostly hispanic immigrants) then all swore that ham on rye causes heart attacks.