Thanks for your question. It is really unfortunate to read about the situation of your friend. Pancreatic cancer is a dreadful type of cancer and has poor prognosis of stage of disease. Moreover, diagnosis is often difficult at earlier stages. Symptoms are even more non-specific at the later and advanced stages of diseases also. The case of your friend is not common. Patients must wake up after surgery. But things can change from person to person. There can be many factors which describes the condition of your friend. Variations in nutrients such a sodium, potassium, calcium etc. are some factor which can lead to coma. Surgery is done to exacerbate these issues. She might also have had a stroke. Possibilities are there that her doctors purposefully let her in coma to allow her body to heal by itself after the major surgery. If her state of coma is due to metabolic abnormalities, her doctor can correct it by taking necessary steps by monitoring her progress. If it is not so possible, there could not be much that can be done medically. Good luck.