In 1979, Pol Pot and the Khmer Rouge were forced from power by the invading Vietnamese. Pol Pot officially resigned the leadership in 1985 but appears to have retained considerable influence.
What could cause fatigue. The cancer itself. Fatigue can be one of the first symptoms of cancer. It could be because there is cancer in the bone marrow and that slows down the production of red blood cells, causing anaemia. A cancer that affects your hormone levels could cause fatigue.
It is known that fatigue can be caused by many different mechanisms, ranging from the accumulation of metabolites within muscle fibres to the generation of an inadequate motor command in the motor cortex, and that there is no global mechanism responsible for muscle fatigue.