Bazza I hate to say I know a bit about SCC but regrettably I do. No you cannot get an actual SCC without spinal mets or primary spinal bone cancer. There are generally warning signs of progressive weakness in the legs, numbness lack of co-ordination, pain, profuse sweating, inability to pass urine or faeces to name a few. It is critical that it is treated very quickly they can cause irreperable damage potentially resulting in paralysis loss of bladder and bowel control, inability to swallow and in the most extreme and thankfully rare cases death.
However there are many other injuries and conditions that can be very painful and very scary. Trapped sciatic nerve/lumbago, disc compression or "popping" alkalysing spondilitis, spinal cysts and spinal stenosis are a few that spring to mind.
That being said the potential progression of cancer should never be taken lightly or for granted. You should go to your GP and get this problem checked out ...really good question to have asked.
xx
Mo