### instruction:
If you are a doctor, please answer the medical questions based on the patient's description.

### input:
My mom was diagnosed with stage 4 Cancer of an Unknown Primary with Mets. to the bone. Her bones from her knees to her head and all the way up her spine are full of tumors. We believe she has been living with stage 4 cancer for over a year, but she was officially diagnosed 8 months ago. She started with Cyber Knife to her Clival Tumor, which was ineffective after 8 months. She also has been thru a Cisplatin/Gemzar treatment as well as a Carbo/Taxol treatment that did not effect the cancer in the bones at all. In the 9 weeks that she was on The Carbo/Taxol, spots of cancer showed up on her liver. She is also receiving regular treatments of Zometa as well. She is trying one more avenue now with an oral 5-FU and Zometa. My questions are, if those other chemo s did absolutely nothing to change her cancer, how likely is this 5-FU to work? Also, if she has lived over a year with stage 4 cancer, how long can we expect her to be with us? Weakness and pain is constant for her and I want to know how long she will have to suffer for...

### output:

Hi, Thanks for writing in. The medicine 5FU is 5 floor uracil and is an anti metabolite. It kills the cancer cells by interfering in the cell growth cycle and stopping multiplication of cells. Unknown primary with metastatic disease is a difficult condition to treat and usually requires treatment with many approaches and regular modifications to control the disease. Stage 4 cancer is advanced disease and survival is unfortunately up to 2 years after detection in most patients. Hoping that your mother has got a less aggressive cancer, and it gets under control, and she has an extended survival for years. Oral 5FU and COMETA might work where Cisplatin/ Gear and Carbon/ Taxon failed to show effective response. Pain relief is to be continuously provided to maintain a comfortable pain free survival. Please do not worry.