Hi All
First if all thank you for your help with details above which gave me enough knoledge to speak to our doctor.
I have been to see her earlier this week and found below answer and details
1. Cancer Subtype : Endometrioid adenocarcinoma.
2. Primary: She siad most likely from endometriosis/adenomyosis -- than Ovary but not sure.

I requested for beow test
1. PD-L1 - she said not important for this type of Gyne cancer. She said MMR is more reliable and because we are pMMR immunotherapy benifits are much lesser (less than 15-20% i.e Dostarlimab)
2. FRA folic acid test - She said not recommended for us. Mainly because treatment is only for re-occurance
3. POLE gene - She said will look in to but may not help.

So current plan for treatment is :
* Complete Chemo therapy - Question here is she said 4 Chemo may be enough but not sure and asked to continue with 6 if she can tolerate.
* RadioTherapy : After chemo.

I have few questions here:

1. Anyone here has been in similar situation where origin of Primary couldn't determined 100% and what have you done?
2. Anyone pMMR and HRD negative with Stage IIIC Endometrial
3. When I asked how do we know if treatment is working? she said because we removed all cancer so CA125 and CT Scan (both are being done regular) may help but its not source of truth and she said we will only know if it re-occure. ---To be honest this answer has made me bit anxious as how come we can't measure anyway if treatment is working or not? Aneone got any idea on this?