Doctors are not very good salespeople
The distinctive feature of Cochin and other university hospitals in France is that they combine healthcare, research, and teaching. As such, they can offer you experimental protocols that “standard” hospitals will only have access to once those protocols have been validated.
Several people advised me not to accept any non-validated protocol, each with their own horrific story to tell. When you add to that the rather poor marketing skills of the doctor in charge (after all, it's not his job), I should have said NO right away. But luckily, I could count on my team of skiers, the Fabulous Traveling Diagnostic Team (remember?). The proposed protocol was actually a combination of two treatments (chemo by pills every day plus four chemotherapy sessions by injection) which had each proven effective on their own, but were suspected to be even more effective when combined. That's what Dr. Zeus explained to me. The alpine skiing team, familiar with this protocol, which is particularly well followed in Lyon under the name Master Protocol (sounds impressive, doesn't it?), approved it and advised me to accept. I have to thank them once again, because without them, I would have been very unsure about my choice.

Yes or no?
That's kind of the problem in these kinds of situations. You don't know anything about it, you're facing a doctor you don't know, who is suggesting a treatment that they honestly believe is the most appropriate. But since it's still experimental, you have to sign a bunch of waivers and read a bunch of documents, some of which aren't exactly reassuring. Basically, you have a big decision to be made quickly, but you're pretty skeptical, especially when you read that you might end up in the placebo group, which will receive a more standard treatment.
The doctor assures you that this won't happen and that he's there to answer all your questions, but as soon as he answers the first one, you sense that something is wrong: you obviously don't have the same level of medical knowledge, and you'll have to get to know each other to understand the subtleties on both sides. What's more, all this is happening via email (oh yes, I went home between the heart exam and Chemo #1 after the initial interview) and the doctor systematically responds with something completely off the mark or sends you back a question as an answer. Communication was a bit muddled at first in my case, but it may be clearer in other cases and with other people. I should point out, however, that I had complete confidence in Dr. Zeus, a kind of intuition, a parallel feeling unrelated to any logical reasoning, which I often listen to and which is often right.
Since my skiers advised me to go for it, I went through the paperwork, signed the forms, and everything turned out fine in the end.