you need educate yourself

your questions indicate that you are totally ignorant about lung cancer.  If you love your grandma, the best thing you can do is to read and understand more about lung cancer so that you can best help her. 

"外婆現在不咳嗽，也沒有痰，就是有肺積水"。Most likely her cancer is treatable, though not curable.  There is fairly good chance that her caner is EGFR positive, and if so she can benefit from drug such as iressa or tarceva.  Of course it will cost some money, to get tested and if positive to buy those made in india pills. 家裏人不幹? - good luck