Just a quick update. Saw my oncologist a few days ago, and she has extended my appointment interval from 3 months to 4 months. Very pleased. She did mention that there is a bit more evidence about aspirin (and hence ibuprofen) preventing spread (metastases) in colon cancer patients. She says there is not enough money for research, and she thinks they might go for metformin (an anti-diabetic drug) first. It also is cheap and off-patent, and so no money in it for drug companies.
She still says that cancer can occasionally stop in its tracks for no reason whatsoever that they know of, or as an odd immune response to a virus, apparently, and that there is no proof that it is the ibuprofen that is helping me, but she is very happy for me to stay on it, and did say that the colon cancer evidence pointed things slightly more in favour of aspirin, ibuprofen etc. I asked if I should have a CT scan as it is 2 years from my last one, but she said to leave well alone, as there was no indication for a scan when I was feeling so well.
Best wishes to everyone, and take note - according to my oncologist, as above, miracles can happen!