newly dx'd stage IIIA endo ca with papillary serous

I am 44 yrs old.  I realize this site is for ovarian cancer, but I was told that my recent diagnosis of stage IIIA endometrial cancer acts like ovarian cancer. aug 15, I had a total hysterectomy including 45 lymph nodes removed. endo cancer with both endometriod and serous papillary features.  46% myometrial invasion, cervial stoma invasion, neg lymph nodes.  suspicious peritenial washing.  because of the suspcious washing they upstaged it to IIIA.

my confusion lies in that a major university/cancer center gynocologic oncologist presented my results to me today and said I have 3 choices:  1) GOG 209 trial; 2) follow tumor board recommendation-internal, external radiation therapy followed by 3 couses of chemo; 3) His recommendation-6 courses of carbo/taxol chemo.

obviously the 3 choice are very different.  I have not been able to find outcomes data on these.

Does anyone have any suggestions?  I would love to hear them.