Interferon is part of the one-two punch combination of drugs used to treat Hep C. Hep C treatment consists of taking Interferon and ribavirin together, not one without the other.
The treatment works in roughly 40% - 80% of the cases, with the cure rate going up the higher the number your genotype is, in very loose terms.
If you are cured, you are cured. It only comes back if you get re-infected. You are considered cured when you have successfully undergone full treatment and there is still no detectable virus six months after treatment. There is a fuller explanation to that however that's a nutshell of it.
Some people take Interferon or a form of it when the treatment has not cured their Hepatitis C to keep it under control. They take what is called "maintenance" doses. This is not a cure. This is using Interferon to prolong your life while one waits to undergo a different type of treatment, wait for new drugs to become fully developed, etc. This is different than what has been said to you.
The statement that Hep C will come back in 8 - 10 years for all people who have had a cure is not true .. so there's no point in even addressing the statement that 90% of people die from it coming back. If it doesn't come back, then obviously nobody dies from something that doesn't exist.
It's not even true that 90% of people will die from Hep C in general. The figure is much lower than that. In general, the thinking is that you are more likely to die of other causes in life than your Hep C.
Hope that helps.
It is my understanding that this is incorrect. Each prognosis is different of course and many factors to consider, but I believe the outcome is much more hopeful than that. I certainly hope so...I am doing tx right now and have been given a much more positive prognosis than this!