In Dumas v. Cooney (1991) 235 Cal.App.3d 1593, the plaintiff alleged that his physicians had been negligent in failing to properly read a chest X-ray and that, as a consequence, they delayed in diagnosing the presence of a malignant lung tumor. At trial, the physicians presented expert evidence that tumors like the one found in the plaintiff are rarely curable, even if diagnosed at a very early stage. In light of that evidence, the physicians argued that the delay in diagnosis did not harm the plaintiff. The trial court gave the jury an instruction that permitted the plaintiff to recover damages from the physicians if an earlier diagnosis would have provided the plaintiff with the possibility of a cure, the possibility of a lengthened life, or the possibility of more comfort. The jury returned a verdict in favor of the plaintiff and, on appeal, the Court of Appeal reversed. The Court of Appeal found that merely proving the possibility of a cure or lengthened life did not establish causation. In rejecting the plaintiff's invitation that it adopt the so-called "lost chance" theory of causation, the court stated: "'Relaxing the causation requirement might correct a perceived unfairness to some plaintiffs who could prove the possibility that the medical malpractice caused an injury but could not prove the probability of causation, but at the same time could create an injustice. Health care providers could find themselves defending cases simply because a patient fails to improve or where serious disease processes are not arrested because another course of action could possibly bring a better result. No other professional malpractice defendant carries this burden of liability without the requirement that plaintiffs prove the alleged negligence probably rather than possibly caused the injury. . . . We cannot approve the substitution of such an obvious inequity for a perceived one.'" (Dumas, supra, 235 Cal.App.3d at p. 1608.)