How to help husband with large painful groin tumor before surgery?

My husband has a rare cancerous tumor in his groin that is larger than a cantaloupe. The skin over has broken down and is now covered with ulcers. It has been extremely painful and he is barely able to walk. He has had 3 rounds of chemo and 4 of immunotherapy and several blood transfusion. Treatment started in October and he has since lost 50 pounds and it continues to grow. They are planning surgery to remove it next month but they say he has to improve his blood levels for it to be successful. He has no appetite and eating is a challenge. He is constant pain. I don't know how best to help him and have been asking for them to remove since day 1. Now I'm scared of the surgery outcome. Anyone have a cancer like this? The biopsy showed urothelial cancer cells but his cystostomy and PETscans show no cancer cells besides tumor.