BlueCross BlueShield of Tennessee Medical Policy Manual

Hematopoietic Stem Cell Transplantation for Central Nervous System Embryonal and Ependymoma Tumors

DESCRIPTION

Hematopoietic stem cell transplantation (HSCT) refers to a procedure in which hematopoietic stem cells are infused to restore bone marrow function in cancer patients who receive bone-marrow-toxic doses of cytotoxic drugs. Hematopoietic stem cells may be obtained from the transplant recipient (i.e., autologous stem cell transplantation) or from a donor (i.e., allogeneic stem cell transplantation). They may be harvested from bone marrow, peripheral blood, or umbilical cord blood shortly after delivery of neonates.

High-dose chemotherapy with hematopoietic stem cell transplantation has been investigated as a possible therapy in pediatric brain tumors, particularly those with disease considered high risk. In addition, the use of HSCT has allowed for a reduction in the dose of radiation needed to treat both average- and high-risk disease, with preservation of quality of life and intellectual functioning, without compromising survival.

CNS Embryonal Tumors

Classification of brain tumors is based on both histopathologic characteristics of the tumor and location in the brain. Central nervous system embryonal tumors are more common in children and are the most common brain tumor in childhood. They are primarily composed of undifferentiated round cells, with divergent patterns of differentiation. It has been proposed that these tumors be merged under the term “primitive neuroectodermal tumor” (PNET); however, histologically similar tumors in different locations in the brain demonstrate different molecular genetic alterations.

Embryonal tumors of the central nervous system (CNS) include medulloblastoma, medulloepithelioma, supratentorial PNETs (pineoblastoma, cerebral neuroblastoma, ganglioneuroblastoma), ependymoblastoma, and atypical teratoid/rhabdoid tumor). Medulloblastomas account for 20% of all childhood CNS tumors. The other types of embryonal tumors are rare by comparison. Surgical resection is the mainstay of therapy with the goal being gross total resection with adjuvant radiation therapy, as medulloblastomas are very radiosensitive. In general, use of autologous hematopoietic cell transplantation in individuals with medulloblastoma who have not received radiation treatment has shown no survival benefit for those individuals considered to be at average risk (i.e., individual age greater than 3 years, without metastatic disease, and with total or near total surgical resection [less than 1.5cm2 residual tumor]).

Ependymoma Tumor

An ependymoma is a neuroepithelial tumor that arises from the ependymal lining cell of the ventricles and is, therefore, usually contiguous with the ventricular system. In children, the tumor typically arises intracranially, while in adults, a spinal cord location is more common. Ependymomas have access to the cerebrospinal fluid and may spread throughout the entire neuroaxis and are distinct from ependymoblastomas due to their more mature histologic differentiation. Initial treatment of ependymoma consists of maximal surgical resection followed by radiotherapy. Chemotherapy usually does not play a role in the initial treatment of ependymoma. However, disease relapse is common, typically occurring at the site of origin. Treatment of recurrence is problematic; further surgical resection or radiation therapy is usually not possible. Given the poor response to conventional-dose chemotherapy, high-dose chemotherapy with autologous hematopoietic stem cell transplantation has been investigated as a possible salvage therapy.

POLICY

See also:

MEDICAL APPROPRIATENESS

IMPORTANT REMINDERS

ADDITIONAL INFORMATION 

The evidence to support hematopoietic stem cell transplantation for the treatment of ependymoma includes relatively small case series. The results of these studies do not report higher survival rates for individuals treated with HSCT compared with standard therapies. The evidence is insufficient to determine the effects of the technology on health outcomes.

SOURCES 

BlueCross BlueShield Association. Medical Policy Reference Manual. (1:2017). Hematopoietic cell transplantation for central nervous system embryonal tumors and ependymoma (8.01.28). Retrieved October 9. 2017 from BlueWeb. (36 articles and/or guidelines reviewed)

Centers for Medicare & Medicaid Services. CMS.gov. NCD for stem cell transplantation (110.23). Retrieved October 24, 2016 from http://www.cms.gov.

National Cancer Institute. (2017, September).Childhood central nervous system embryonal tumors treatment (PDQ®). Retrieved October 10, 2017 from http://www.cancer.gov.

National Cancer Institute. (2017, September). Childhood ependymoma treatment (PDQ®). Retrieved October 10, 2017 from http://www.cancer.gov.

National Comprehensive Cancer Network. (2017). NCCN Guidelines for the Treatment of Cancer (NCCN Guidelines®). Central nervous system cancers (V.1.2017). Retrieved October 10, 2017 from the National Comprehensive Cancer Network.

Odagiri, K., Omura, M., Hata, M., Aida, N., Niwa, T., Goto, H., et al. (2014). Treatment outcomes and late toxicities in patients with embryonal central nervous system tumors. Radiation Oncology, 9, 201. (Level 4 evidence)

Raleigh, D., Tomlin, B., Buono, B., Roddy, E., Sear, K., Byer, L., et al. (2017). Survival after chemotherapy and stem cell transplant followed by delayed craniospinal irradiation is comparable to upfront craniospinal irradiation in pediatric embryonal brain tumor patients. Journal of Neuro-Oncology, 131 (2), 359-368. Abstract retrieved October 11, 2017 from PubMed database.

Sung, K., Lim, D., Lee, S., Yoo, K., Koo, H., Kim, J., et. al. (2012). Tandem high-dose chemotherapy and autologous stem cell transplantation for anaplastic ependymoma in children younger than 3 years of age. Journal of Neurooncology 107 (2), 335-342. Abstract retrieved October 24, 2016 from PubMed database.

Winifred S. Hayes, Inc. Medical Technology Directory. (2013, December; last update search December 2016). Autologous stem cell transplantation (ASCT) for metastatic primitive neuroectodermal tumor (PNET). Retrieved October 10, 2017 from www.Hayesinc.com/subscribers. (30 articles and/or guidelines reviewed)

ORIGINAL EFFECTIVE DATE:  7/14/2012

MOST RECENT REVIEW DATE:  11/9/2017

ID_BA

Policies included in the Medical Policy Manual are not intended to certify coverage availability. They are medical determinations about a particular technology, service, drug, etc. While a policy or technology may be medically necessary, it could be excluded in a member's benefit plan. Please check with the appropriate claims department to determine if the service in question is a covered service under a particular benefit plan. Use of the Medical Policy Manual is not intended to replace independent medical judgment for treatment of individuals. The content on this Web site is not intended to be a substitute for professional medical advice in any way. Always seek the advice of your physician or other qualified health care provider if you have questions regarding a medical condition or treatment.

This document has been classified as public information.