cancer in the omentum

My brother was just diagnosed with what is called cancer of the unknown primary.  Basically means the doctors do not know where the cancer originated, however they know it is in his omentum.  Doctors are stating his cancer is treatable, but not curable.  However, treating with chemo is not a long term solution.  I'm curious what type of treatment(s) did your oncologist recommend?  My brother did start chemo(folfox).  Thanks, Dan