Physicians were able to achieve complete remission in 97% of patients in the study — a remarkable but not really unexpected result, say experts.

According to Christine Patte, MD, pediatric oncologist at the Institut Gustave Roussy in Villejuif, France, the current study was designed based on the findings of three previous trials.

"Throughout the trials, survival increased due to a better understanding of the disease, the recognition of prognostic factors to which intensity of treatment was adapted, the lessons learned by the failures, and to a better management of the immediate toxicity of the treatment," adds Patte.

The French pediatric oncologists treated a total of 561 newly diagnosed patients younger than 18 years old with varying stages of B-cell lymphoma or ALL. The study was conducted July 1989 through June 1996, and each patient was followed for at least 20 months after treatment.

The patients were put into one of three treatment groups, according to the extent of their disease. Patients who had limited disease, along with other findings suggesting a good prognosis, had a more limited treatment program; whereas those with invasive cancer received more intense therapy.

The majority of patients was in group B, and received treatment consisting of four phases. Because many patients in this group have a large tumor burden, it is important to get their kidney function under control, says Theresa Vietti, MD, professor and oncologist at the Washington University School of Medicine Children’s Hospital in St. Louis and member of the American Cancer Society’s editorial board for patient information.

As these patients begin treatment, they can experience what is known as tumor lysis syndrome, where such massive breakdown of tumor tissue can lead to clogging of the kidneys. For this reason, a lower-dose preparatory "prephase" treatment is given to help get them in good physiological shape.

Nearly all (92.5%) of the patients treated were still living after five years. The event-free survival, meaning the patients recovered with no recurrence of their disease, was 91%.

"This cure rate was expected, knowing the results of the previous studies, and we were happy to confirm it," says Patte. Interestingly, Patte notes that the drugs used to treat patients in this study were not new. Most of the drugs have been around for about 30 years, but are just used in more effective combinations and doses today.

Vietti says that though patients in the US are treated with similar types of intensive therapy, comparing European and US approaches to treating cancer is like comparing apples and oranges. The main difference lies in how the patients are grouped, which determines how intense their therapy will be.

"Some of the patients in this study got very intensive therapy — more than we would have given," explains Vietti. "And some of their patients, we would have treated more aggressively."

Despite any differences in treatment regimens, Vietti says that European and US physicians have very similar success in treating childhood cancers. "We’ve known about these studies and have admired them, but I think ours are very good, too," notes Vietti.

Survival Rates Have Increased

Len Lichtenfeld, MD, FACP, a medical oncologist and medical editor for the ACS, observes that as a result of research begun during the 1960s, survival rates in childhood cancer have steadily increased as doctors developed the highly effective treatments available today. However, Lichtenfeld notes that oncologists realize the children who have these diseases are quite diverse.

"Much of the research during the past decade has focused on ways to identify which children can be cured with milder chemotherapy that causes less severe side effects, and which children need very intensive treatment in order to survive," says Lichtenfeld, noting that despite enormous advances, there is still room for progress. "The hope of many researchers is that as they gain greater insight into the behavior of these cancers, they will be able to develop new treatments that are at least as effective as current ones, yet far less toxic," he concludes.