Back of the Envelope

On Monday, John Edwards promised miracles:

"We will do stem cell research," he vowed. "We will stop juvenile diabetes, Parkinson's, Alzheimer's and other debilitating diseases. America just lost a great champion for this cause in Christopher Reeve. People like Chris Reeve will get out of their wheelchairs and walk again with stem cell research."

Now it disturbs me how people like John Kerry and John Edwards brush aside the ethical questions as if they're not worth considering. Sacrificing a human life to heal yourself is the stuff of thousands of stories, many of them stories of horror and black magic and science-run-amok. Western civilization (and, I hope, others, but it's the western literature I'm familiar with) has long recognized this powerful temptation to evil, while praying that such a morally repugnant practice would never become accepted. While you can in good conscience--I hope--argue that this is not what is going on in embryonic stem cell research, how dare Kerry and Edwards not even feel the need to make the argument! The greatest evils are those you never question, never think about, refuse to consider.

But is there any truth in what they're promising? From what I understand, embryonic stem cell research hasn't even been particularly promising. In at least one case, it backfired horribly:

A carefully controlled study that tried to treat Parkinson's disease by implanting cells from aborted fetuses into patients' brains not only failed to show an overall benefit but also revealed a disastrous side effect, scientists report.

In about 15 percent of patients, the cells apparently grew too well, churning out so much of a chemical that controls movement that the patients writhed and jerked uncontrollably.

The researchers say that while some patients have similar effects from taking too high a dose of their Parkinson's drug, in this case the drugs did not cause the symptoms and there is no way to remove or deactivate the transplanted cells.

(Hat tip Brain Shavings)

Read the whole thing. I'm sorry to say this, but it reads a lot like one of those cautionary SF stories. The responses of the doctors are enlightening:

For now, Dr. Greene said, his position is clear: "No more fetal transplants. We are absolutely and adamantly convinced that this should be considered for research only. And whether it should be research in people is an open question."
...
The one glimmer of hope came from assessments by neurologists before the patients had had their first dose of medication in the morning. By that measure, the 10 patients under age 60 who had had the fetal cell implants seemed better than those who had had sham surgery, with less rigidity, although their tremor was just as bad.

Dr. Freed hailed that result, saying, "It was a clear-cut improvement."

And, he added, the fetal cells survived in most patients' brains.

"I would be disappointed if people used a strict clinical trial approach," Dr. Freed said. "This study is about multiple phenomena."

Others were less enthusiastic, pointing out that finding subgroups after the fact who may have benefited suggests a hypothesis for future studies, not evidence of an effect.

"We try to teach everybody that you have to identify beforehand what's the primary outcome," said Dr. William Weiner, the director of the Maryland Parkinson's Disease and Movement Disorder Center and a professor of neurology at the University of Maryland School of Medicine in Baltimore, referring to the measure of success determined before the study began. "In this case, they picked a subjective assessment by the patients themselves, which I think is a very good one."

And so, Dr. Weiner said, when the patients noticed no improvement, "the study was negative."

In addition, Dr. Langston said, even if a subsequent study confirmed that the surgery had an effect on the condition in younger patients before they took their medicine in the morning, and even if there was a way of preventing the terrible side effect, the operation would still hardly be a breakthrough. Parkinson's disease is almost always a disease of the elderly, he noted, adding that well under 10 percent of patients who would be candidates for the surgery are younger than 60.

The wiggling and writhing movements first emerged a year after the operation, showing up in five of the younger patients who had at first appeared to benefit from fetal cell surgery — three who had the operation in the initial phase of the study and two who had it a year later, when they learned that they had originally had a sham surgery
...
Dr. Freed said his group was now implanting less fetal tissue and putting the tissue in a different area of the brain, hoping to avoid the devastating side effects. But, he said it would be a mistake to stop doing the surgery altogether.

"To say that you can't do or shouldn't do human research because the research has uncertain outcome, I think would be a bad decision," Dr. Freed said.

I feel sorry for the patients, and I prefer to believe that even in their desperation they considered and resolved the ethical dilemma for themselves. Dr. Greene at least shows humility and a willingness to learn from his mistake. I feel less sympathy for Dr. Freed, who throughout the article comes across as unrepentant, even going so far as to grasp at straws to call this a partial success.