I just had to cancel 3 holidays due to bowel cancer had insurance and got our money back, the bank insurance should pay you out as this was not a pre excisting illness and the holiday was booked b4 your wife had the biopsy, good luck with results  hope all goes well.

Hi,

So sorry to read that your wife's bowel cancer has recurred.

As in so many things to do with cancer the answer is really "it depends". Don't do anything hasty. The first thing should be to check with your insurers BEFORE you cancel the holiday, you should be able to do this by phone. If you declared her cancer in 2013, if they didn't exclude that condition from her insurance cover and if you were unaware that it had started growing again when you booked, you should be covered. 

If it turns out she isn't covered, you might want to check whether you would be better off postponing the holiday or transferring the holiday into someone else's name. You may need to pay an admin charge for these but the insurance will probably have an excess charge anyway. I once had to do this for a holiday due to illness. At that time, postponing and re-booking only cost me a £50 admin fee, whereas the insurance excess was £50 each and there were two of us booked. 

Good luck

Dave