"cancelled operation"

At the end of May I had a uterine scan at WGH which revealed that I had a small thickening in the wall of my womb.I had an appt at the gynaecology dept on 12th of June where the consultant was unable to get a biopsy and I was told that I would need a hysteroscopy. I duly had a pre-op assessment ready for this procedure. I received notification to present myself at St Albans hospital for day surgery on the 8th of July. I arrived at the hospital and was checked in- the anaesthetist then came and told me that they would not do the procedure because of my medical history.and that my case would be transferred back to WGH. I would like to know what is the purpose of pre-op assessment if medical concerns are are not raised with the relevant departments earlier. I am now waiting for a date from WGH for this procedure to be carried out--I have a history of cancer and I am finding this delay very upsetting and completely unacceptable. i was sent home from the hospital with no apology (my husband is 80 and had to come and pick me up again immediately on arriving back home from dropping me off) I can understand that there was a reason for the cancellation but surely this should have been picked up earlier- the seems so be a complete lack of communication between department and nobody seems to be willing to admit to lack of care..