Newbie - dad with newly diagnosed stage 4

Hello everyone,
My dad (70) has recently been diagnosed with stage 4 esophageal cancer, that has spread to lungs, stomach and liver. His gen. practitioner reviewed his chart this past Wednesday and estimated that he had 3 months left.

He's been having trouble eating for a few weeks now, and it's gotten worse. Loss of apetite from physically not being able to swallow foods, and also mentally because certain smells and the thought of some foods make him nauseous. Over the weekend he showed signs of improvement in apetite and eating, but that faded and he hasn't eaten anything since yesterday morning. He tried drinking an Ensure, but vomited that up soon after. Now he's having dry heaves, and has lost more weight. This is taking a toll on his emotions and will.

continue...

Wednesday he's scheduled for an endoscopy and biopsy, with the results being rushed and then an appt with the Oncologist. This morning my mother tells me that dad is saying 'what is the use of it now?' and he's not feeling the need to do the procedure.

What are some realistic options in this situation? At this point, is surgery or chemo or radiation at stage 4 with this much spread to other organs even something that could be helpful? Even if only to get him more comfortable and able to eat?

Some background:
5 years ago he had a heart valve replacement, mechanical. He's been on blood thinners ever since. 5 weeks ago he developed a clot in his right ankle, and this lead to doctors finding the cancer on a barium swallow and CT scan. 2 weeks ago he got a second clot in his left ankle, and they have placed an 'umbrella' into his vein to catch any clots that could travel upwards. The pain from the clots and circulatory problems is very intense and he can only move around in a wheelchair for 5-10 minutes before having to get back into bed. Pain meds had been making in moderately bearable. He was prescribed morphine pills since vicodin and norco were not doing enough.

Friday he started on Lovenox injections to prep for the endoscopy, and stopped the thinners. This really helped reduce the swelling and pain in his legs, and we imagine it's because the clots are breaking up. He has not had to take any morphine, and has been able to reduce the amount of norco he's been taking.

His apetite improved Friday and Saturday, as well did his spirits. But, on Sunday he was only able to eat a small amount in the morning, and nothing but tea since then.

Thank you for reading/listening and thank you in advance for any advice.