Sorry to hear about your stepfather. It sounds similar to my case. I could only sip water when I was diagnosed with large cancerous tumor in my lower esophagus. I've had a feeding tube since then and do 6 feedings of ISOSOURCE plus water everyday. I've had 3 rounds of chemo and the latest PET scan showed 40% reduction, and now I can eat soft foods.
Tomorrow I go for CT Simulation and hope to get schedule for 6 weeks of radiation and chemo 5 days a week. I've lost about 15 pounds hope to start gaining it back. I hope you can find something that works for your stepfather. Best wishes and prayers.