The survival rate for non-Hodgkins lymphoma is pretty high. The 10 year survival rate is over 50%.
The fact that Lucy is so young, and she led a very healthy lifestyle prior to her diagnosis, gives me alot of hope that she's going to pull through.
I also found an article that proves chemotherapy reduces PCB levels accumulated in the body. So if PCBs did cause Lucy's cancer, the chemo should be helping to get rid of them!