What’s new in neuroblastoma research and treatment?

Important research into neuroblastoma is under way right now in many university hospitals, medical centers, and other institutions around the world. Each year, scientists find out more about what causes the disease and how to improve treatment.

Genetics of neuroblastomas

Researchers now have better lab tests to look for changes in the genes of neuroblastoma cells. They have made a great deal of progress in recent years in figuring out which neuroblastomas are likely to be cured with standard treatment, and which will need more aggressive treatment.

For example, using newer lab tests, researchers have found that certain DNA changes on the short arm of chromosome 6 (6p22) are more likely to be seen in neuroblastomas that grow more aggressively. More recently, researchers have found that neuroblastoma cells in older children are more likely to have changes in the ATRX tumor suppressor gene. Tumors with this gene change tend to grow more slowly, but they are also harder to cure. This may help explain why younger children with neuroblastoma tend to do better in the long term than children who are older when they are diagnosed.

Doctors are now looking to use these and other findings to help aid in choosing the best treatments. Newer staging systems and risk group classifications, which take advantage of some of these findings, should be in use within the next few years.

Treatment

Survival rates for neuroblastoma have gotten better as doctors have found ways to improve on current treatments.

Chemotherapy

Doctors continue to search for the best combinations of chemotherapy drugs to treat neuroblastoma.

Several chemotherapy drugs that are already used to treat other cancers, such as topotecan, irinotecan, and temozolomide, are now being studied for use against neuroblastoma. Some newer drugs that work in different ways from standard chemotherapy drugs are being studied against neuroblastoma as well. Examples include bortezomib, vorinostat, nifurtimox, and lestaurtinib.

Other studies are looking to see if children with low or intermediate risk neuroblastoma can be treated with less chemotherapy. The goal is to still have the same good results, but with fewer side effects from treatment.

Stem cell transplants

Doctors are also trying to improve the success rate with high-dose chemotherapy and stem cell transplants, using different combinations of chemotherapy, radiation therapy, retinoids, and other treatments. Some clinical trials are studying the use of more than one stem cell transplant in the same patient (known as a tandem transplant). Others are looking to see if using stem cells donated from another person (an allogeneic transplant) might help some children with hard-to-treat tumors.

Retinoids

Retinoids such as 13-cis-retinoic acid (isotretinoin) have reduced the risk of recurrence after treatment in children with high-risk neuroblastoma. Newer, potentially more effective retinoids, such as fenretinide, are now being studied in clinical trials.

Newer forms of treatment

Knowledge about what makes neuroblastoma cells different from normal cells may lead to new approaches to treating this disease. Newer forms of therapy that target neuroblastoma cells more specifically than standard treatments are now being studied in clinical trials. For example, doctors are now studying medicines that specifically target the machinery of neuroblastoma cells, such as drugs that inhibit the ALK pathway or aurora A pathway.

One example is crizotinib (Xalkori), a drug that targets cells with changes in the ALK gene. Up to 15% of neuroblastomas have changes in this gene. In an early study, crizotinib was found to cause some neuroblastomas to shrink, although it’s not clear how long this might last. Researchers are now looking to see if adding second type of drug, called an mTOR inhibitor, might help make this drug more effective.

The monoclonal antibody ch14.18, which targets GD2 on neuroblastoma cells, is now used routinely for children with high-risk neuroblastoma, to help immune system cells find and destroy the cancer cells. Clinical trials are now testing the effectiveness of several other antibodies that target GD2. One example is hu14.18-IL2, an antibody that is linked to interleukin-2 (an immune-boosting cytokine). Early results have found that this antibody/cytokine combination may help some children in whom other treatments are no longer working.

Several cancer vaccines are also being studied for use against neuroblastoma. For these vaccines, modified neuroblastoma cells or other substances are injected into the body to try to get the child's own immune system to attack cancer cells. These treatments are still in the earliest stages of clinical trials.