At the 46^th annual meeting of the American Society of Clinical Oncology (ASCO) in Chicago earlier this summer, researchers from St. Jude Children's Research Hospital and the Pediatric Brain Tumor Consortium (PBTC) revealed findings of a pediatric brain tumor study using an experimental drug that targets the underlying genetic makeup of the tumor.

 

The innovative research focused on a new way to attack the tumors by blocking the Hedgehog pathway that is linked to approximately 20 percent of medulloblastomas. The study represents the first showing that the drug can be safely administered to children and also suggested that the drug is showing early signs of efficacy in this patient population, with some children still on treatment almost a year with no progression of disease. The study involved children with medulloblastomas that had persisted or returned despite standard treatment with radiation and chemotherapy. The cure rate for recurrent medulloblastoma is less than 5 percent.

 

These early, promising findings prompted the green light for pediatric research to advance to a larger Phase II study scheduled to open later this year, and to increase the number of patients on the young adult study. The Division of Cancer Treatment and Diagnosis and the National Cancer Institute are PBTC trials sponsors.

 

"Medulloblastomas are the most common malignant brain tumors in children," said Amar Gajjar, MD, co-chair of the St. Jude Department of Oncology and principal investigator of the PBTC trial. "The trend in treating children with these cancers is toward targeted therapies like this one, which block key signaling pathways and disable the cancer's ability to function or reproduce. We know that this Hedgehog pathway is important in the growth of these especially hard-to-treat tumors."

 

Also at the ASCO annual meeting, St. Jude investigators announced that childhood cancer survivors diagnosed later with non-melanoma skin cancer may be at increased risk for having a malignant tumor within 15 years.

 

Gregory Armstrong, MD, assistant member of the St. Jude Department of Epidemiology and Cancer Control, said nearly one of five survivors in the Childhood Cancer Survivor Study (CCSS) who were diagnosed with basal or squamous cell skin cancer developed another more aggressive cancer within 15 years. The CCSS involved 14,358 childhood cancer survivors whose cancer was diagnosed between 1970 and 1986; the average survivor was age 36.

 

"These findings suggest non-melanoma skin cancers are a potential marker for survivors who are at risk for future invasive malignancies," Armstrong said.

 

Les Robison, PhD, St. Jude Epidemiology and Cancer Control chair, CCSS principal investigator and the study's senior author, pointed out that childhood cancer survivors are known to be at increased risk for additional cancers, which remain a leading cause of disability and death among those who beat cancer the first time.

 

"This study," said Armstrong, "is the first to track the risk of multiple malignancies in a large group of aging cancer survivors."

 

In May, St. Jude investigators announced that a multicenter trial they led achieved 71 percent survival after three years, marking a 20 percent improvement over previously reported U.S. rates. More individualized therapy and better supportive care helped push the survival for children with acute myeloid leukemia (AML) to a higher rate three years after diagnosis. AML, a cancer of certain white blood cells, is diagnosed in about 500 U.S. children and adolescents annually. Even though cure rates for acute lymphoblastic leukemia (ALL), the most common childhood cancer, have soared to better than 90 percent, long-term survival among AML patients has lagged.

 

Results of the study, which involved 230 young AML patients treated at St. Jude and six other U.S. hospitals, are among the best reported nationally or internationally, said Jeffrey Rubnitz, MD, PhD, a member of the St. Jude Oncology department.

 

This study, which featured several firsts—the first use of minimal residual disease (MRD) to guide the timing and makeup of later chemotherapy, for example, and the first time all patients received antibiotics after each course of chemotherapy in hopes of preventing bacterial and fungal infections—was published in the June edition of The Lancet Oncology.

 

"We focused on getting the maximum benefit from existing therapies and applying lessons learned from earlier studies to identify and treat patients who faced the highest risk of relapse," Rubnitz said.

 

U.S. News & World Report recently named St. Jude, the nation's largest research-based pediatric brain tumor program, as the leading children's cancer hospital in the 2010-11 Best Children's Hospital rankings. St. Jude received the top overall score summarizing quality of care. Earlier this year, The Scientist magazine ranked St. Jude among the annual "Best Places to Work in Academia" for the fifth consecutive time. This year, St. Jude was ranked second, only behind Princeton University.

 

The St. Jude Children's Research Hospital-Washington University Pediatric Cancer Genome Project remains St. Jude's most ambitious initiative in the race to find out how cancer begins and grows in children. Launched earlier this year, the $65 million, 3-year project represents the largest investment to date aimed at understanding the genetic origins of childhood cancers, with a team dedicated to decoding the genomes of more than 600 childhood cancer patients who have contributed tumor samples for this significant, historic commitment.