This is the cancer my mum has (she has high grade uterine serous carcinoma)- I don’t know if i have much information to offer. 

My mum has been tested (and found positive for) the BRCA1 mutation, I don’t know how common this is in terms of this type of cancer but I believe it is what caused mums cancer. Has your friend ever been tested? 

Mum’s also on some medication called PARP inhibitors, they’re still on the trial phase in the USA but she’s been allowed compassionate use of them, funded for by an American drugs company. She got on these through ULCH (university of London college hospital I think), and I believe she referred herself there. They have worked for a while for her. 

Unfortunately, mums cancer is now incurable. But in terms of medication, the PARP inhibitors have been positive and given her a year of life she wouldn’t of had otherwise

i don’t know how much help this has been, but try to stay away from google. I’ve found it’s only ever scared me, and if you want more information then you could try looking at macmillan - they have LOADS of stuff on different cancer types that is designed not to scare you when you already feel vulnerable 

I very much hope your friend is as okay as she could be after hearing this rubbish news. Sending lots of love and hugs xxxxx