Life expectancy after transplant is hard to gauge. Most of the statistics that are available are based on longer-term experience, meaning that some of the data goes back to include 30 years of transplant history, so the numbers may skew the success rate down, and the numbers are very difficult to apply to any patient, because many studies are retrospective and include a wide variety of disease statuses at transplant, different methods of conditioning, and different methods of dealing with complications like graft versus host disease. It is believed that outcomes are getting better, but most of the survival data that we see is based on 1 and 2 year outcomes. It is generally believed that if a person can go 2 years without relapse after transplant that the odds of a relapse become pretty low and long-term survival increases dramatically. Some of the complications include late infections and GVHD which can be challenges for years after transplant.
http://www.mdsbeacon.com/news/2011/0...term-survival/
http://jco.ascopubs.org/content/29/16/2230.full
Unfortunately, we cannot predict outcomes, but some of the evidence shows that lower disease burden at the time of transplant is an important factor in determining success. I cannot find the article now, but the National Institute for Health had a study showing that it was important to be below 12% or 13% blasts heading in for higher success rates, but there are certainly other very important factors such as underlying health conditions as measured by the comorbidity indices.