Your mother has been diagnosed with endometrial cancer, which is the most common type of malignancy of body of uterus. Treatment is mostly involving surgery followed by radiotherapy and or chemotherapy according to the stage of disease. If it's very advanced disease in which surgery is difficult then only we need start the treatment with chemotherapy. Otherwise surgery will be planned at the earliest. All definitive treatment (curative ) involve surgery in the type of cancer your mother is having. It would be helpful if you can share her PET CT report, which will help rule out distant metastasis and your MRI report which will help in local staging . It's based on the staging we decide how to proceed.