Recently read about the casein in dairy products causing cancer to proliferate. 50 pounds is a very huge loss and not a good sign at all. I would insist on your doctors figuring out what is happening!

Wow! My husband really struggled with this also.
The weight loss was one thing but the loss of muscle is something else. Entirely too weak to exercise which I am thinking would increase appetite. Are you able to do any exercise? He lost almost the same as you did in about a four month period. Miraculously his appetite perked up after the third round of BR. He regained 15 lbs. in one month. Today is his fourth and final treatment. He will start PT soon. Hopefully this helps give him his strength back. I have no magic formula for gaining the weight. The only thing that worked for my husband was setting an alarm and eating something every two hours. Even if it's just a package of peanut butter crackers. Hope you find something that works for you.
Katie

I was starving and I was told they were going to put in a tube. No way. Food didn't taste, smell, and I just couldn't eat. My Doctor said I was scheduled for a 10 am surgery to put in a tube. He asked, last chance to eat protein, what will you eat? I just thought, jerky? In the morning, there was a one pound bag on my tray. I opened it and tried a small bite. By 10 am, the bag was half gone. Jerky saved me. Sweet Baby Ray's was different but tasted sweet too. Good luck.