I know how you feel. My husband was diagnosed with bladder cancer, muscle invasive, Nov 2018. He did 3 rounds of chemo prior to the surgery to remove the bladder. Everything looked great, even at his surgery follow up appointment everything looked good then the first of April I had to take him to ER for severe abdominal pain, CT showed that there was a tumor on the left adrenal gland that was hemorrhaging. Upon further evaluation they found lesions on his liver as well. So like your Mom, he too started immunotherapy using Keytruda. They did a pet scan about a month after finding the lesions on liver and the cancer had spread even more. It was then in his rib bones along with multiple other areas. The oncologist gave him a year maybe. He spent a week in the hospital every month due to pain and each time they found more lesions. Finally in July the oncologist came in and said obviously the Keytruda is not working and his genetic testing came back with nothing. The dr told us he had 2-3 months at best. My husband was done, he didn't want anymore treatment. He was 57 years old and died 2 1/2 weeks later at home. I know how hard this is for you, especially when it's your Mother, not to mention your father having it as well. 2nd opinion depends on if she is up to that. Sometimes quality of life outweighs quanity as hard as that is to swallow. I finally had to give in to that. I wish you the best and your family is in my prayers.