Thank you for your query.
It is heartening to know that your son is doing well. It is very difficult to predict the survival rate
till the staging of the tumour is known. Yes, chemotherapy
does cause loss of hair.
I do not suggest that you get a feeding tube
inserted. Appetite does fall down while on chemotherapy and shall gradually return to normal. One should encourage your son to have small frequent meals.
I hope I have answered your query to your satisfaction.
Wishing your son all the best.