In fact, the more I learn about cancer, the more I come to realize that most likely there is not a "silver bullet" approach that works for every case. If I had to bet on something, though, I would say that boosting your immune system to be more effective recognizing and disposing of cancer cells would be the way to go. However, current advances on this front are far from satisfactory and sometimes even cause more damage than benfit in the long run.
Speaking of silver bullets, I had to google to see that the "Robert Beck Protocol" was. I think I had encountered it before, but did not look further into it due to the lack of convincing evidence about it and the pseudo-sciencey vibe emanating from most of the information surrounding it (questionable claims, testimonial evidence, conspiracy theories and lack of reproducibility).
Thank you for your comment, @lucky.digger!