Hello, Stage 1 grade 3 breast cancer means the tumor is that is larger than 10 mm but 20 mm or smaller. As they have removed lymph nodes, it means cancer spread to lymph nodes. The cancer pill is tamoxifen to be taken for 5 years. Lymph node involvement makes it mandatory to remove them and the arm gets swollen up. It happens in almost every case of breast cancer. It is called lymphedema. Treatment for lymphedema is exercise which helps improve lymph drainage. Specific exercises will be advised by your doctor or physical therapist. Diet and weight management help. Eating a healthy diet and controlling body weight is an important part of treatment. Keep the arm raised. Raise the arm above the level of the heart when possible lets gravity help drain the fluid. Prevent any infection. It’s important to protect the skin in the affected area from drying, cracking, infection and skin breakdown. Use massage therapy. Massage by someone trained in lymphedema treatment can help move fluid out of the swollen area. It s difficult and painful but the lymphedema gets resolved slowly and the blistering also stops eventually. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Pallavi M., Anesthesiologist