Add to circle. Enlarge Photo. car batteries are highly recyclable-AAA. A concern raised over upcoming electric-drive cars--the all-electric 2011 Nissan Leaf, the 2011 Chevrolet Volt, and the 2012 Toyota Prius Plug-In Hybrid --is what happens to their lithium-ion battery packs once the car's life ends.
Stage 4 cancer refers to the spreading of cancer to various sites in the body. It is a complex type of cancer to treat because it may often involve multiple organ systems such as the liver, lung and brain. However, stage 4 cancer patients shouldn't lose hope. Immunotherapy can oftentimes make all the difference in the world.
Number staging systems. Number staging systems usually use the TNM system to divide cancers into stages. Most types of cancer have 4 stages, numbered from 1 to 4. Often doctors write the stage down in Roman numerals. So you may see stage 4 written down as stage IV. Here is a brief summary of what the stages mean for most types of cancer.