Results of a trial by the Children's Oncology Group indicate that children with intermediate-risk neuroblastoma can be successfully treated with a shorter duration and lower doses of chemotherapy than are currently used.
Findings from the phase 3 trial reported in the September 30, 2010, issue of the New England Journal of Medicine may change the approach to treating the disease, which affects 650 children in the United States each year.
"Our goal was to reduce the level of chemotherapy needed to effectively treat intermediate-risk neuroblastoma patients while maintaining an excellent rate of survival, and that is exactly what we did," said senior author Katherine Matthay, MD, chief of pediatric oncology at UCSF Benioff Children's Hospital. "This trial will lead to permanent treatment reductions in our protocol for treating this disease and will have a significant impact on the hundreds of children who are diagnosed with neuroblastoma each year."
The researchers aimed to reduce exposure to chemotherapy by at least 40% while maintaining the same 90% survival rate achieved in earlier trials using higher doses. The study involved 479 children with newly diagnosed stage 3, 4, or 4S disease.
The researchers examined samples from each patient's tumor to assess the cancer cells, and categorized them as having either favorable or unfavorable disease biology based on the findings. The 323 patients with favorable biologic features received four cycles of chemotherapy (carboplatin, etoposide, cyclophosphamide, and doxorubicin) while the 141with unfavorable features received eight cycles. The children also underwent surgery to remove or biopsy their primary tumor.
For patients with favorable tumor biology, chemotherapy treatments were reduced in length by 70%, from 10 cycles over 9 months to four cycles over 3 months. Any of these patients who failed to respond after four cycles received an additional four. For patients with unfavorable biology, treatment length was reduced by 40%, from 10 cycles over 9 months to eight cycles over 6 months.
Overall survival at 3 years was 96%. Among patients with favorable disease biology the 3-year survival rate was higher, 98%. Those with unfavorable biology had a 93% survival rate. According to Matthay, if a patient with intermediate-risk neuroblastoma survives for 3 years without relapse, the patient almost always is cured.
"It is my hope that we will be able to continue reducing the amount of chemotherapy we give to certain groups of neuroblastoma patients, so we can improve the long-term quality of life for these children and not have to worry about them having any secondary cancers," Matthay said.