Getting a second, or even a third, opinion can be so helpful. And with telemedicine, you can get it from anywhere. The best cancer centers in the US are Mayo Clinic, MDAnderson, Dana Farber, Sloan Kettering, and Massachusetts General Hospital. They will want your medical records. Write down your questions in advance. Ask why they recommend what they are recommending. Ask about the pros and cons of each particular treatment. And then see if you can get the treatment you want in Canada. It will cost hundreds of thousands of dollars in the US if you don’t have American health insurance.
Good luck!