What is your professional opinion on the refusal of treatment chimiotherapy treatment, beneficence or autonomy? And why?

Autonomy.

what is your professional opinion on the refusal of treatment chimiotherapy treatment, beneficence or autonomy? And why?

I hear echoes in your question. Couldn't choose one or the other based on your expression, let alone "why".

Would you like to, or could you, provide more detail?