Metastatic Adeno Carcinoma - Please Help

My mum had a hysterectomy in 2008.She had complained about heavy bleeding during her periods. On diagnosis we found there was a fibroid growth in the uterus. The gynecologist suggested to remove the uterus and the ovaries. After the hysterectomy,the fibroid was given for biopsy which resulted to be negative for malignancy test. In April 2011 she developed the symptoms of severe back ache and loose motion. On diagnosis we got to know about the metastatic Adenocarcinoma. The primary was unknown and still is. But the doctors are suspecting it as ovarian cancer.She has undergone 6 cycles of chemotherapy( paclitaxil + carboplatin).She had CA-125 level up to 310 which got increased up to 698 after the first cycle of chemo. From there it got down to 63 after 6 cycles of chemo. Currently she is on oral Chemotherapy(Xeloda - 500mg). After 6 cycles of chemo the latest PET CT scan shows metastasis to bilateral pelvic lymph nodes, retro peritoneal lymph nodes,right retrocrural lymph node, omen-tum and left adrenal gland. Doctors are not sure of the surgery.If the surgery will help her.If they are able to remove the lumps completely. They say they will try to keep very less residue in the body.As in, they will try to remove as much as they can. But they are not sure if they are able to completely remove it or not. I don't know what to do. Can't figure out what is the right decision. They say it is an inter-operative decision. I don't want the doctors to open up her abdomen and decide to back out and close it back again. They say even that might be the case. I Can't afford to give her more pain. She is already in pain. She has lot burning sensation in the stomach now. Anybody who knows anything about this please help me.Any info you guys have might help me. Please Kindly Reply. God Bless All.