I think it's fair to say that squamous cell throat cancer survival rates are more or less the same as survival rates for throat cancer in general, because squamous cell
is by far the most common kind. It accounts for 90% or more of cases.
The survival rate depends on what stage it's at when you find it. There's stage I, which is a pretty small tumor that's just in one place. I found on the NIH site that 90% of people at this stage can be cured!
It can go up as high as stage IV, where the tumor is bigger and has spread to other places. Info on the overall stage IV survival rate, which should be comparable to the squamous cell throat cancer survival rates, is kind of hard to find, but the best source I found said about 30% of patients live five or more years.