Private MD News

Hope for treating childhood tumor found through gene sequencing

Category: Cancer Detection and Tumor Markers

A cancer that is most commonly found in the muscle and soft tissues of children may have a new treatment available after gene sequencing lab test results were released this month. The findings, published in the scientific journal Cancer Cell, bring fresh hope to those with the rare and fast-spreading tumor.

Members of the St. Jude Children's Research Hospital-Washington University Pediatric Cancer Genome Project found that by using drugs that intensify a process called oxidative stress, the cells of rhabdomyosarcoma died off. Additionally, the drugs could fortify the efficacy of chemotherapy against the tumors from the soft tissue cancer.

Oxidative stress is caused by an imbalance between the production of reactive oxygen and the body's ability to repair the damage. This study offers the first insight into the benefits of using drugs already on the market to treat cancer cells. Following gene sequencing of the rhabdomyosarcoma tumor, the team was also able to provide new clues as to why tumors come back even after treatment.

"Overall, survival for patients with recurrent rhabdomyosarcoma is just 17 percent, and until now nothing was known about how tumors evolve in response to therapy," said Michael Dyer, Ph.D., corresponding author of the study and a member of the St. Jude Department of Developmental Neurobiology.

Using their results, the researchers plan to expand their biopsies to rhabdomyosarcoma tumors that recur in patients.

"Studies like the current one involving rhabdomyosarcoma are giving us a close-up look at the way cancer evolves in response to treatment," explained fellow study author Richard Wilson, Ph.D., director of The Genome Institute at Washington University School of Medicine in St. Louis.

Based on the blood testing and drug screening of tumor samples from patients, this study could lead to new options in therapies and cancer treatments.

Facts on rhabdomyosarcoma
A malignant tumor of the muscles that are attached to bones, this cancer is most commonly found in children. It can be found in many places, such as the head and neck, as well as the urogenital tract.

The cause of this cancer is currently unknown, as it is very rare and only a few hundred cases are reported in the United States every year. Although gene mutations and birth defects may play a part in elevating the risk of developing rhabdomyosarcoma, the large majority of children with the cancer do not possess any known risk factors.

It is a very difficult cancer to detect, as many of its symptoms are not substantial enough to warrant further screening. Early diagnosis is essential because rhabdomyosarcoma, also known as soft tissue sarcoma, can quickly spread to other parts of the body. Some tests may include blood testing, CT scans, biopsies and MRIs.

Aggressive treatment is necessary with rhabdomyosarcoma, yet long-term survival is achievable for most patients. Chemotherapy or radiation, or a combination of both, would be used to treat the cancer before or after surgery.

The Pediatric Cancer Genome Project
St. Jude Children's Research Hospital and Washington University School of Medicine in St. Louis collaborated and launched the Pediatric Cancer Genome Project in 2010. Some of the most aggressive and rarest cancers that affect children have been examined by the PCGP. They have completely sequenced the normal and cancer genomes of 700 young cancer patients. The group works to compare the completed genomes in order to find differences in DNA structure that identify genetic mistakes that lead to cancer.

Through their studies, they have improved the knowledge of childhood cancers down to their genetic origins, as well as helped advance the potential of future diagnostic and treatment tools for cancer.