Do Cancer Cells Survive After Death, And If So For How Long?

The cancer survives only as long as the tissue survives, so it depends upon where the cancer resides.    Since tissue is dependent upon the oxygenation of the blood (and the blood then supplies oxygen to cells of tissue), the cancer cells die along with the tissue.  Oxygenation ceases with the cessation of the lungs and heart function.  Tissue begins to die within minutes.

Organs--SUCH AS heart, liver, kidneys and pancreas ---are less sensitive to loss of blood flow and oxygen than the brain and can survive
for longer periods without losing their function, and as long as the tissue stays viable through blood and oxygen, the cancer can also live.  Someone who is brain dead can sustain tissues and their dependent cancer cell growth.

• Hearts and lungs are particularly sensitive to being without a blood supply
  and must be transplanted within four to six hours of retrieval.
  
• The liver and pancreas must be transplanted within 12 hours
  
• The kidneys within 24 hours.

Again, when the tissue dies, the cancer dies, as well.

Even if a person is not moving, all their body parts will still be receiving a blood supply and thus oxygen which all cells, including cancer cells, need to survive, grow and multiply. The blood flow may be reduced because the body knows that the extremities (i.e. Limbs) don't need to function as much as if they were being used every day to walk on etc. But they will certainly still be receiving blood to keep the healthy cells alive... And so the cancer cells will still be receiving whatever they need also.