You can simply use more than one mirror commands like this:
lftp -u uid,pwd \
-e 'mirror -c /home/dcr96/TCGA/dir1; mirror -c /home/dcr96/TCGA/dir2; exit;' \
So all you need is some shell code which produces such command line from your list.
You could also generate such lftp script, which might be more easy to review and debug before executing.
open -u uid,pwd serapeum2.qib.pbtech
# auto-generated from the list
mirror -c dir1
mirror -c dir2
Note the mirror command accepts a local target directory. You would need this to keep the complete paths in case of longer paths:
mirror -c path/to/dir1 path/to/dir1