Virginia, Im very sorry to hear about your mother! I went back and read your posts from 2008 to see what she has been thru. Unfortunately, I am not familiar with how to treat mets to the lungs. I know chemo for oral cancer will not cure it, the chemo would only be for palliative care.
Have you sought out a second opinion at a cancer center? That would be the very best thing to do to help your mother and to know if she will be able to get thru this. The countries top cancer treatment facilities may be her only shot. Here is a link to the list.
Cancer center list Best wishes!!!!