Point of clarification: you might want to give a specific country/place because legal and cultural shifts vary. For example, in the Philippines that expectation is not there as I understand it. Recently spoke with someone whose father has a stage IV thyroid cancer (anaplastic) with mets everywhere and a fistula leading out to his skin. The doctors told the family and not the patient and his medical team is so far telling him he has a severe infection. The father in question is cogent and according to his son legally still in control of his life. He said its just how things work with terminal illnesses there. This is almost in direct opposition to US policy in healthcare where the patient might not want their information shared with anyone (spouse/next of kin). So, I don't know if it is really universal among contemporary healthcare systems that Doctor-Patient confidentiality is the expectation.