What is the scope of a physician's duty to disclose medical information to their patient?

[27 Cal.3d 291] In Cobbs v. Grant (1972) 8 Cal.3d 229, 104 Cal.Rptr. 505, 502 P.2d 1, this court considered the scope of a physician's duty to disclose medical information to his or her patients in discussing proposed medical procedures. Certain basic characteristics of the physician-patient relationship were identified. "The first is that patients are generally persons unlearned in the medical sciences and therefore, except in rare cases, courts may safely assume the knowledge of patient and physician are not in parity. The second is that a person of adult years and in sound mind has the right, in the exercise of control over his own body, to determine whether or not to submit to lawful medical treatment. The third is that the patient's consent to treatment, to be effective, must be an informed consent. And the fourth is that the patient, being unlearned in medical sciences, has an abject dependence upon and trust in his physician for the information upon which he relies during the decisional process, thus raising an obligation in the physician that transcends arms-length transactions." (Id., at p. 242, 104 Cal.Rptr. at p. 513, 502 P.2d at p. 9.)