Chemo has finished, all four rounds done. We were told that it has worked better than expected and that there is a massive shrinkage in all tumours. We've now been told that there are two options, be scanned every three month and go from there or for my grandad to be giving pemetrex every 3 weeks. We were told even though this was an option, the doctor did not advise it as it can cause damage to kidneys and other long term effects. 
I am really confused. They have said that the cancer is not currently active and the pemetrex would 'keep it at bay', how can you have chemo to keep the cancer at bay when it's not currently active? 
origionally we were told it would be immunotherapy, but now that does not appear to be an option. 
 

We are all usure of what to do. In November when he was diagnosed with stage 4 metastic lung cancer we were told he would have 3-6 to live without treatment, but now they are saying the chemo has worked better than they ever could have hoped, but now everything has stopped we are scared the cancer could come back quickly.