For a child with cancer, treatment in a carefully supervised clinical trial is not just another option — it is usually the best option, said a childhood cancer expert.

"Studies show children treated in clinical trials have better outcomes than others," said Laura Bowman, MD, director of blood and marrow transplant at the AFLAC Cancer Center, Children's Healthcare of Atlanta.

That's because children in clinical trials get state-of-the-art treatment either by itself, or along with a new twist scientists have reason to believe may improve it, said Bowman.

According to the National Cancer Institute (NCI), about 8,600 US children were diagnosed with cancer and about 1,500 children died from the disease in 2001. While this makes cancer the leading cause of death by disease among US children under age 15, cancer is still relatively rare in this age group.

Over the last half of the 20th century, progress in childhood cancer diagnosis and treatment has transformed a once uniformly fatal disease into a group of cancers that are now curable in most children, according to the Children's Oncology Group, an NCI-supported clinical trials cooperative.

With this success has come the realization that the goal of curing all children with cancer is achievable, NCI investigators said. It has also led to a heightened recognition of the need to reduce long-term treatment effects and improve quality of life.

Bowman said doctors treating the most common childhood cancer, acute lymphoblastic leukemia (ALL), now use clinical trials to typically focus on identifying high-risk and low-risk patients, based on the biology of each individual child's leukemia.

That focus allows them to identify children likely to do well with less treatment, and others who may need more, Bowman noted. The children each get the treatment proven best for that group, or that treatment plus a therapy meant to improve it, such as a second bone marrow transplant while in remission, Bowman said.

Such clinical trials have brought the cure rate for childhood ALL from almost zero in the late 1950s to between 85% and 90% now, Bowman said.

Childhood brain tumor trials have brought major advances in radiation delivery and in neurosurgery techniques in the last 10 years, and those advances form the basis of further trials to improve outcomes and reduce long-term side effects, she said.

In childhood neuroblastoma, cure rates have not improved as much as in ALL and childhood brain tumors, so doctors are now adding innovative treatments such as cancer vaccines and monoclonal antibodies. These therapies attack substances plentiful only on neuroblastoma cells, sparing most normal cells from harm, said Bowman.

Because it is widely recognized that clinical trials provide the best outcomes among childhood cancer patients, insurers typically pay for treatment in a clinical trial, said Bowman.

It's unquestionable that clinical trials have played a huge role in the dramatic improvement in childhood cancer cure rates in the last 30 to 40 years, said Bowman.

But the focus for doctors participating in clinical trials is on providing the best possible care for each patient in a trial, because only treatments that improve some patients' outcomes can point to how to do the same for others, Bowman said.

That knowledge helps parents to understand that most of what is done in clinical trials is refinement rather than experimentation, and to understand the difference, she said.

"We sit with them and say, 'These are treatments we know work for this disease and this is how we use them to get the best response to treatment. And in this trial we're adding a second therapy, and I can't tell you whether that's going to improve outcome or not, but that's our goal. We know the first one will improve their chances of cure, and all the patients will get that,'" said Bowman.

Parents are increasing their understanding of the benefits of clinical trials for children, said Bowman. With details on the concept and location of most trials available online and centers open to having parents contact them directly, most childhood cancer patients are now treated in trials.

"With outcomes better and a very high quality standard of care the rule, it's not hard to understand why most parents opt for a clinical trial for their child when available, and they are widely available," said Bowman.