I lost my oldest cat Teddy to Squamous Cell Carcinoma behind his left eye last year so I'll keep a special place in my prayers for Sam.
I feel for you regarding Teddy. I lost my twelve year old Minnow to bone cancer three years ago. She was a fantastic cat. And her death was very sudden. By the time she showed symptoms of being ill, it was only three weeks before she died, despite our best efforts.
And Merry Christmas to you ans LB, too.