How is neuroblastoma treated?
Neuroblastomas, usually those that are staged as "4S," may go away spontaneously or regress to the point that they can be removed entirely by surgery. Other neuroblastomas spread rapidly.
Treatment depends on the cancer's stage, the primary tumor's location, the characteristics of the tumor, and the patient's age. Several modalities (ie, surgery, chemotherapy, radiation, immunotherapy) may be used in a patient to treat the cancer, especially with high-risk tumors, which are the most difficult to treat. Cure is much more likely with the lowest-stage neuroblastomas. Unfortunately, about half of neuroblastomas aren't discovered until they've already spread to the bone and bone marrow, meaning that treatment becomes more complicated.
Treatment may include:
- Surgery. In most cases, surgery is needed to remove the primary tumor, often after several cycles of chemotherapy to shrink the tumor. Stage-1 tumors are most able to be removed entirely by surgery.
- Chemotherapy. Chemotherapy refers to the use of any of a group of drugs whose main effect is either to kill or slow the reproduction of rapidly multiplying cells. Cancer cells absorb chemotherapy drugs faster than normal cells do (but all cells are exposed to the chemotherapy drug). For the treatment of neuroblastoma, chemotherapy drugs are given intravenously (injected through a vein). Five or more cycles of chemotherapy are usually needed to shrink the tumor sufficiently so that surgery can be performed.
- Radiation. Radiation therapy is a form of cancer treatment that uses high levels of radiation to kill cancer cells or to keep them from growing and dividing. Radiation may be used following surgery to reduce the risk of the cancer relapsing (recurring), and it may be used together with chemotherapy at sites where the cancer has spread. Targeted forms of radiotherapy may be used to minimize the risk of radiation damage to tissues or organs that surround the tumor.
- Immunotherapy. Usually used after surgery, immunotherapy aims to train the body's immune system to attack neuroblastoma cells that remain after chemotherapy or radiation. The treatment uses a monoclonal antibody that is injected into the bloodstream, which searches for neuroblastoma cells and once identified signals the body's immune system to attack them.
- Stem cell transplant. Stem cell transplant allows high doses of chemotherapy and radiation to be used to treat neuroblastoma. Stem cells are removed and stored prior to the treatments and then reinfused to replace bone marrow cells destroyed by chemotherapy and radiation.
- Specialized treatments. Isotretinoin is a drug used in patients treated with immunotherapy who are in remission. It stops immature neuroblastoma cells from growing and dividing, thus reducing the risk of a relapse. An anti-angiogenesis drug, which restricts the growth of blood vessels that feed the tumor, may be tried in patients who don't respond to standard treatments.
What if the cancer relapses?
Relapse is usually caused by neuroblastoma cells that survive treatment and are too small or spread too diffusely throughout the body to be detected. Relapses in the central nervous system (such as the brain) are more difficult to cure and may be treated with monoclonal antibodies to deliver liquid radiation directly to the neuroblastoma cells at the site of relapse. Remission may be extended by using monoclonal antibodies with other forms of treatment.
Treatment for relapses outside the central nervous system depends on previous treatments but usually requires multiple modalities.