Sorry to hear the news and for the lad...
And, although maybe its not really my business, a single thing can I tell you made, that can help you a lot, because Im researching since yeas in the topic:
Cancer is really NOT a disease (or a whole brand business issue, as the medical care made of it). Its a symptom, that just tell you, you have to CHANGE you way to eat (and live). Eat more vegetables and fruits, and try to avoid the rest (mostly the industrial mass made food, white sugar, alcohol, oil and meat)...
Because the whole is about to a cell mutation on the stomach in your body, where your natural aerobic cells
( Aerobic organism: https://en.wikipedia.org/wiki/Aerobic_organism
) are forced to change themselfs into anaerobic cells
( Anaerobic organism: https://en.wikipedia.org/wiki/Anaerobic_organism
), as the diet become through the years more based in GLUCOSE, fat and Carbohydrate (meat) and they dont get anymore that much oxygen from the vegetables and fruits...
I wish you anymay a Speed recovery, mate!