Advice for second line treatment after first line chemo - serous endometrial carcinoma stage 4

Hello all

Like many, I have stalked this forum for a long time trying to glean advice and information. Your posts have made something confusing and scary far more lucid and "workable". For that, I think you all so much but, in particular, the forum's resident superstar Daloni who has helped me more than she can know!

Actually, I am a bit of an imposter as it is my very much loved mum that I have been gleaning information for. She is 74 and was told last April that she has stage 4 serous endometrial cancer. It was - as you can imagine - a massive shock as she had never had a symptom and it was only discovered on a routine ultrasound concerning a pessary (no idea what that it is...). Mum was really quite heavy with disease apparently including a few small spots on her lungs which of course meant stage 4 and incurable.

Anyway, thanks to Daloni's eloquent posts, I was able to get her to see Dr Kristeleit as a private patient. She is a calm, matter of fact but quite reassuring oncologist at the forefront of many of the clinical trials so we felt quite safe in her hands. Mum went through the 6 cycles of carboplatin and paclitaxel with almost no side effects and we were very hopeful when Dr K said after the third cycle that her CA125 had come down to almost normal from 175. Indeed, after the 6 cycles had finished, mum was in complete remission and had had an excellent response to the chemo. Her CA125 was 25. Great. Fabulous. What an amazing result. I imagined given such a response we would have at least a year all clear... but 7 months later Dr K has said that there are two "small, suspicious lymph nodes at the base of the spine". It was a real blow. Bizarrely - and here's the twist - her CA125 has gone down to 23!

So, now the battle starts up again and I don't know what course to follow. Mum is BRCA negative, hormone negative, MSI stable and no Lynch. Dr K is suggesting mum participates in the Copelia trial but my concerns are: 1) there is only a 1 in 3 chance of getting the trial drugs; 2) olaparib is a parp inhibitor and I thought parp inhibitors only worked with a positive BRCA status 3) she has no symptoms whatsoever, she is likely to become chemo resistant somewhere down the line (and treatment options will then be limited so i want to push that day as far into the future as possible) - ultimately, does it make sense when you are incurable using a valuable chemo when you have no symptoms?

So, I just wanted some advice as to the best course of action. I don't think there are any other useful UK trials on offer - there is a great one in the US of niraparib which is effective irrespective of BRCA status but, of course, a little bit of trek to participate in that one! Keytruda is effective only in MSI-H women so I understand so what alternatives are there?

I would be so grateful if any ladies out there with stage 4 serous and a recurrence could tell me what they did next and how it worked out for them. I just want to take all this away from my mum and make her better - i don't know what I'd do without her.

Cath x