it seems your step dad is not responding to conventional chemotherapy
post surgery that is why the disease has recured locally as well as in other parts of the body.I wonder if the new molecules which is called targetted chemotherapy has been tried on your dad which could give some respite. you can discuss with your doctor asking his opinion about the same.
if already tried then it is better to stop any form of chemotherapy and give him palliative comforting medication under your doctors guidence.
Dr. J. Ticku