"I don't know, usually just slips out but usually before i can draw breath these people just launch into their long speeches"
That just it though, Sarah. When they ask how you are, and you quickly say 'fine', a lot of people will think
'Oh god, I've put my foot in it. Dear Sarah has probably had her fill of people talking about her illness. That'll be why she said "Fine" like that. Everybody probably asks and now I've asked too. Ohh, what'll I say to take her mind off that'
and so they start to babble about all the things they've been doing. In an ideal world, people would be able to read between the lines and reach the right conclusions, not the wrong ones, but it's not always that easy.
Maybe if you tried to give a more honest reply (and I think that's something we should all try to do) then you would get a more useful reaction. It won't be easy to do, but it doesn't have to be huge changes. When people ask how you are, start by trying to answer with a short phrase. 'Not so great today', or whatever.
I think there will be many more people than you think, who would want to give you a caring response, if you can allow them to see that it's okay to do that.
I'm so sorry your cancer has recurred, Sarah, and I'm sorry for all the things you have got to face in order to deal with that. (I'm not sorry about your wonderful forthcoming December wedding, though!!!
)