Colorectal Cancer Diagnosis

My patient has colorectal cancer, was told that her cancer was Benin, and was discovered early, theres no worries. his daughter, a nurse told him. (But he is smart, and I am the nurse in charge of her.)
In the Asian context, her daughter argued that the diagnosis by revealing to her mother, she would "lose the hope of life".
To this end, it has been informed of a "benign" and suffered a colorectomy, which was in vain, and now is undergoing radiotherapy.

I was the nurse who has been invited to witness the consent of his colorectomy.

Scenario - patient kept in the dark about the diagnosis, but is still undergoing the procedures, and consent of the signs. I am head nurse, assisted by consent, and does not say the patient's diagnosis (the patient's right receiver at the request of the patient's daughter)

I want to know how screwed am I? "In other words, what are the legal and ethical issues, I am obliged to give this scenario?

scenario in regard to Singapore context.
Thx

Personally, I do not want my name on the papers as a witness if my patient does not know their diagnosis.I think everyone has the right to know their prognosis.
In nursing school, our instructor told us never to sign as a witness to nothing, that is families responsibility.The legal possibilities are too great if there were problems with the road.The daughter could very easily turn on you saying she never told you not to tell your patient's diagnosis.I leave the sign of the family as a witness, only to protect yourself.Everyone is so "Sue" happy, you need look for yourself.

I do not know Paris, but the United States, the retention of patient information is a kind of big deal.

I have some questions .. Is DPOAE girl? The patient suffers from dementia and unable to make their own decisions? I can not imagine not knowing my own diagnosis!

Well first of all in the nursing code of ethics we first and foremost duty to our patients beyond foresee everything!. Secondly if the girl is the MPOA and the patient has the right to know his prognosis, diagnosis, and all alternative treatment under the law of informed consent. Th epatient the right to this knowledge. I recommend callign for an ethics consult immediately because it is an injustice to your patient and you have the position of being the advocate for your patient.