Hi cant give you much advice on your poor sons cancer but knowlage of it all is a good start .on here there is an ask the nurse if you leave a question and they will answere any question if poss if you want to spk to someone there is the McMillan helpline the cancer research and the marie currie helpline they will chat and put you through to one of there cancer nurses they were very helpful and kind the numbers are free just google numbers it helped me understand as much as you can with this rotton disease all credit to your son but just being there if he needs help is best you can do realy realy ime a dad myself .there will be others who have more  experiance than i but very best wishs to you and your son at this awful time .regards paul .ps there maybe financial help for you and your son mcmillan can advise you on that if you live in uk as people from all over the world post on here