honestly, i don't know what to tell you. i am sure you know at stage IV,
there is not much we can do.
If the cancer cell has specific mutation, there are erlotinib/gefitinib and
crizotinib that are targted therapy. Only if your relative has those
specific mutation. Those meds are expensive and only prolong survival. There
is no cure for stage IV lung cancer. 5 year survival is only 1-2%
realistic speaking, your relative should do whatever he/she wants to do
while still alive
palliative care/symptom management, such as for pain, GI movement, cough,
fatigue should be incorporated into treatment to improve quality of life.
咳嗽 is very common in lung cancer, is there sputum/mucous or dry cough?
乏力 may be related to anemia, what's hemoglobin level?