SAN FRANCISCO - A woman whose doctor says marijuana is the only medicine keeping her alive can face federal prosecution on drug charges, a federal appeals court ruled Wednesday.

The ruling was the latest legal defeat for Angel Raich, a mother of two from Oakland suffering from scoliosis, a brain tumor, chronic nausea and other ailments who sued the federal government pre-emptively to avoid being arrested for using the drug. On her doctor's advice, Raich eats or smokes marijuana every couple of hours to ease her pain and bolster her appetite.

The latest legal twist once again highlighted the conflict between the federal government, which declares marijuana an illegal controlled substance with no medical value, and the 11 states allowing medical marijuana for patients with a doctor's recommendation.

The Supreme Court ruled against Raich two years ago, saying medical marijuana users and their suppliers could be prosecuted for breaching federal drug laws even if they lived in a state such as California where medical pot is legal.

Because of that ruling, the issue before the 9th U.S. Circuit Court of Appeals was narrowed to the so-called right to life theory: that the gravely ill have a right to marijuana to keep them alive when legal drugs fail.

Raich, 41, began sobbing when she was told of the decision that she was not immune to prosecution and said she would continue using the drug.

“I'm sure not going to let them kill me,” she said. “Oh, my God.”

The three-judge appeals panel said that the United States has not yet reached the point where “the right to use medical marijuana is 'fundamental' and 'implicit in the concept of ordered liberty.”'

However, the court left open the possibility that Raich, if she was arrested and prosecuted, might be able to argue that she possessed marijuana as a last resort to stay alive, in what is known as a “medical necessity defense.”

“I have to get myself busted in order to try to save my life,” Raich said.

One of her physicians, Frank Lucido, said in an interview last year that Raich would “probably be dead without marijuana.” Lucido, of Berkeley, was not immediately available for comment Wednesday.

Leaders in the medical marijuana movement said they would continue fighting.

“This is literally a matter of life and death for Angel and thousands of other patients, and we will keep fighting on both the legal and political fronts until every patient is safe,” said Rob Kampia, executive director of the Marijuana Policy Project.

New Mexico is poised to become the 12th state to allow medical marijuana under a bill lawmakers approved Wednesday. Gov. Bill Richardson, a strong supporter of the measure, is expected to sign it.