Unable to swallow pureed food with oesophageal cancer

Hello. 
My mum was diagnosed with oesophageal cancer in March. She is not receiving any treatment due to her age. She is now having difficulty swallowing pureed food. Liquids are still ok at present. 
She has recently been on a course of steroids and this really improved her condition. Is this something doctors would prescribe long term? 
what are the next stages now she is unable to swallow pureed food? Who should I be asking for advice from? Mum is still coherent and gets up every day. Definitely more tired than usual, and slightly more confused. 
Do we still attempt puree? Although I am concerned about aspiration. I think she’s getting fed up of soup. Bless her. Any help would be more than welcome please