My mother in law has lung cancer , spread to both lungs, lymph nodes, windpipe & brain. She had radiation & gamma ray radiation. I have noticed a huge change since last week, she has extreme swelling in both feet & ankles & they started seeping fluids. She cries out in extreme pain in both legs from just above knee down her leg. Says it feels like someone is picking at her bones with a knife. Is this a sign that it may have spread to her bones? Or that things are shutting down?