When researchers test new drugs on humans, they start with phase 1 clinical trials. Those studies aren't aimed at seeing whether a drug works; instead, researchers are looking at the drug's safety, and trying to figure out the highest dose that people can tolerate without troublesome side effects.

Then the drug can move on to larger trials testing its effectiveness.

With it comes to childhood cancer treatments, kids may be eligible for a phase 1 trial if their own cancer is terminal.

So essentially, those children are doing the trials to benefit other kids with cancer in the future, explained Dr. Eric D. Kodish of the Cleveland Clinic, who worked on the new study. But it has not been clear whether parents fully understand the point of phase 1 trials.

Kodish and his colleagues found that they often do not.

In interviews with 60 parents, they found that only one-third seemed to have a "substantial understanding" of the scientific purpose of phase 1 trials. And 35 percent showed little to no understanding.

That was despite the fact that all of the parents had just met with their child's oncologist for an "informed consent conference" on enrolling in a phase 1 trial.

It's not certain whether some parents thought their child could potentially be cured by the experimental drug, according to Kodish. But that is a worry, he said.

The study, which appears in the Journal of Clinical Oncology, included families at six U.S. hospitals that run phase 1 pediatric cancer trials. Kodish's team recorded the informed consent conferences, then interviewed parents about a week later.

They looked at how often doctors explained three main "scientific concepts" of phase 1 trials: testing drug safety, finding the best dose and dose escalation - where one group of kids in the study gets a certain dose, and then if that dose is safe, the next group of kids gets a higher one.

Overall, doctors explained those concepts only about a quarter to half of the time. Only days later, many parents couldn't describe the three concepts during interviews.

Kodish said it's not clear if those parents actually thought the trial offered a chance at a cure - or if they would've kept their child out of the study if their understanding had been better. (Almost all of the families ended up enrolling their child in a phase 1 trial.)

But the findings show that doctors "should be trained in strategies and techniques" for better explaining phase 1 trials, the researchers write.

"We need to help parents understand that the logical reason to participate is to help future kids with cancer," Kodish said.

He added that minority parents and those with less education might need particular attention. In this study, they were less likely to understand the goals of the trials than white and better educated parents were.

Phase 1 trials are necessary for new treatments to be developed. "This study is not saying that these trials are unethical," Kodish stressed.

He added that families often say they are glad they participated. "After their child has passed away, parents say they get some comfort from knowing they've helped other kids."

But it's very important, he added, that families are fully informed before enrolling their child in such a trial. They need to weigh that choice against the other options for their child; if they want to travel or spend time with relatives, a phase 1 trial might not be the choice for them.

And, Kodish said, families may instead want to choose hospice or palliative care, which is aimed at making a child as comfortable as possible at the end of life.

A "surprising" finding, Kodish noted, is that in nearly all cases, parents brought their child to the informed consent conference.

Kodish said that in the 1980s, when he did his training, you would not see kids at these meetings. He thinks the big shift shows how much adults' attitudes have changed, so that children are now part of the decision-making.

But that also means everyone, parents and kids, need to fully understand what phase 1 trials are, he said.

SOURCE: bit.ly/U5kPZP Journal of Clinical Oncology, online October 15, 2012.

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