Anaplastic oligodendroglioma
The anaplastic oligodendroglioma is a neuroepithelial tumor of varying dignity that presumably originates from oligodendrocytes , a cell type of the glia . In the classification of brain tumors of the World Health Organization (WHO), anaplastic oligodendrogliomas are assigned to grade III. In the course of the disease, they can degenerate into a WHO grade IV glioblastoma . The vast majority of oligodendrogliomas occur sporadically, without a certain cause and without inheritance within a family.
Overview
The ( malignant ) anaplastic oligodendroglioma belongs to the group of diffuse gliomas and arise in the central nervous system ( brain and spinal cord ) from precursor cells of oligodendrocytes. This tumor occurs mainly in middle adulthood with a frequency peak in the 4th and 5th decades of life (approx. 0.11 / 100,000 new cases per year).
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diagnosis
The most important diagnostic procedure is magnetic resonance imaging (MRI). Occasionally, outside of routine diagnostics, the metabolism in the tissue is displayed using positron emission tomography (PET). The diagnosis is confirmed by a tissue examination following an operation. Anaplastic oligodendrogliomas often show a loss of genetic material . About 50 to 60% of WHO grade III anaplastic oligodendrogliomas have combined allele losses on the short arm of chromosome 1 (1p) and the long arm of chromosome 19 (19q). This change is usually referred to as the "1p / 19q-Co-Deletion". It is to be rated as favorable for the patient and makes a response to radiation or chemotherapy more likely. Anaplastic oligodendrogliomas have an increased number of tumor cells, the tumor cells and their nuclei vary significantly in appearance. In addition, according to the WHO classification, necroses and proliferating vessels are also permitted, so that there is diagnostic overlap with glioblastoma.
therapy
Tissue removal during an operation serves to confirm the diagnosis of an anaplastic oligodendroglioma. In addition, surgery can help reduce symptoms caused by the tumor. The most complete removal of the tumor visible in the MRI is preferred, provided the location of the tumor allows this. Since the cells of an anaplastic oligodendroglioma have already migrated into the surrounding healthy brain tissue when the diagnosis is made, complete surgical removal of all tumor cells is not possible. That is why further treatment is always necessary after an operation. For follow-up treatment, radiation therapy and chemotherapy with temozolomide or a combination of procarbazine , lomustine and vincristine (PCV scheme) are possible. The marker “1p / 19q code deletion” plays an increasingly important role in the selection of therapy and therapy combinations.
The substances procarbazine, lomustine and vincristine have been used in chemotherapy for anaplastic oligodendroglioma since 1975 . Since then, new therapy options have been tested regularly as part of therapy studies in order to improve treatment.
Course and prognosis
A definitive cure is not possible in anaplastic oligodendrogliomas of WHO grade III. Compared to anaplastic astrocytoma , however, the course is more favorable. The relative survival rate after 5 years: ages 20-44, 71%. Age 45-54, 61%. Age 55-64, 46%.
Individual evidence
- ↑ Swiss Brain Tumor Foundation: Anaplastic Oligodendroglioma. In: www.swissbraintumorfoundation.com/. Accessed in 2013 .
- ^ Central Brain Tumor Registry of the United States. Retrieved February 5, 2020 .
- Jump up ↑ Philip H. Gutin, Charles B. Wilson, AR Vansantha Kumar, Edwin B. Boldrey, Victor Levin, Malcolm Powell, KJ Enot: Phase II study of procarbazine, CCNU, and vincristine combination chemotherapy in the treatment of malignant brain tumors. In: Cancer. 35, 1975, p. 1398, doi : 10.1002 / 1097-0142 (197505) 35: 5 <1398 :: aid-cncr2820350524> 3.0.co; 2-c .
- ^ Survival Rates for Selected Adult Brain and Spinal Cord Tumors . 7th November 2017.
