Hi - I believe (but will check!) the rate of recurrance for RCC is something like 40-50%, but it depends on the initial stage it was DX the first time around. The earlier the stage, the less likely recurrance is. I know the longer it doesn't recur, the better - ie, the less likely it IS to recur at all. But it can definitely definitely recur years and years and years later! I think the record I've heard of so far is something like l6. That's why, yes, you must NEVER assume it's gone for ever, however reassuring your doctors are. Keep those scans going! For the rest of your life.
The upbeat thing is that, even if it DOES recur, because you'll have been scannign regularly (it's about once a year at least, isn't it folks who know?), if they DO find something, it won't have been there too long, or got too nasty. Plus, these days, the powerful new drugs like Sutent, plus the new tehcniques like cybeknife etc, mean that recurrant tumours (they will be classed as mets - metastases - because the original primary tumour is long gone), are far more treatable than they used to be.
I take it you have had a full body (chest and abdomen) CT scan, plus a head and neck scan, to check that, even if it was DX early stage as seems, there are no signs of mets anywhere currently in your body? It really is worth having this done, whatever the stage you were DX at. Depressingly, the docs now think that cancer can start to metastasize earlier than thought originally, so constants vigilience is needed by the patient.
All the very best to you - and HOW FORTUNATE your cancer was caught so early. Only around half of kidney cancer is caught at stage one, which has a five year suvival of nearly 90% (and people here will tell you they've lasted decades longer than that!)
Julie.