I’m not sure you can say any reassuring and as someone who’s parents have both had cancer (my mum died and my dads is prostate) it really is t helpful when people try and be reassuring.
If it’s cancer you need your friends to recognise it’s that and what that entails. If your having tests for cancer it really doesn’t help and feels like people are trying to avoid the reality your facing IME.
I’ve also lost 3 friends to cancer this year (all died within months of diagnosis of stomach cancers) - we are all in our 40’s.
Personally I find it better if people invite me for a coffee and just listen. Or if I dont want to talk about it chat shot about TV or the weather or something.
But in a positive note my dad was diagnosed 2019. 6 months chemo (not fun during Covid!) and he went into remission.
Now takes a combination of cancer drugs and hormone injections. Is 76, at the gym 5/6 days a week, PSA lower than average for his age and holidays frequently.
That is reassuring in itself. However I’m also fully aware of the reality that when the drugs stop working …… and people jog regaining those fears or pretending that fact doesn’t exist make me feel worse not better!
Best way forward? Ask your friend what she needs and wants and be there to listen.