Second primaries can happen. Most are NOT related to the type of treatment received, but other unique individual biological factors, and mechanisms by which the person came to the cancer in the first place. Odds are in your favor to not be in this group once you are 5 years out, but that is no guarantee. What in life really is guaranteed? The under two year group has the highest rate of recurrence. There are treatment related issues, even malignancies, but these are most often associated with radiation such as the group that ends up with mandibular sarcomas from radiation about year 10. The percentage of people that get these is very small by the way, but is does happen. In my own experience when someone that I know dies from this disease my anxiety issues act up, and I suspect while that only makes me human, it still rattles my cage. For sometime thereafter, everythng that goes bump in the night, an earache, a small irritation in my mouth is my cancer coming back. Welcome to survivorship.