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The standard initial treatment is to remove as much of the tumor as possible without worsening neurologic deficits. Radiation therapy has been shown to prolong survival and is a standard component of treatment. There is no proven benefit to adjuvant chemotherapy or supplementing other treatments for this kind of tumor. Although temozolomide is effective for treating recurrent anaplastic astrocytoma, its role as an adjuvant to radiation therapy has not been fully tested.
Quality of life after treatment depends heavily on the area of the brain that housed the tumor. In many cases, patients with anaplastic astrocytoma may experience various types of paralysis, speech impediments, difficulties planning and skewed sensory perception. Most cases of paralysis and speech difficulties can be rehabilitated with speech, occupational, physical, and vision therapy.
A 2017 meta-analysis compared surgical resection versus biopsy as the initial surgical management option for a person with a low-grade glioma. Results show the evidence is insufficient to make a reliable decision. The relative effectiveness of surgical resection compared to biopsy for people with malignant glioma (high-grade) is unknown.
For high-grade gliomas, a 2003 meta-analysis compared radiotherapy with radiotherapy and chemotherapy. It showed a small but clear improvement from using chemotherapy with radiotherapy.
Temozolomide is effective for treating Glioblastoma Multiforme (GBM) compared to radiotherapy alone. A 2013 meta-analysis showed that Temozolomide prolongs survival and delays progression, but is associated with an increase in side effects such as blood complications, fatigue, and infection. For people with recurrent GBM, when comparing temozolomide with chemotherapy, there may be an improvement in the time-to-progression and the person's quality of life, but no improvement in overall survival, with temozolomide treatment.
A mutational analysis of 23 initial-low grade gliomas and recurrent tumors from the same patients has challenged the benefits and usage of Temozolomide. The study showed that when lower grade brain tumors of patients are removed and patients are further treated with Temozolomide, 6 out of 10 times the recurrent tumors were more aggressive and acquired alternative and more mutations. As one of the last authors, Costello, stated "They had a 20- to 50-fold increase in the number of mutations. A patient who received surgery alone who might have had 50 mutations in the initial tumor and 60 in the recurrence. But patients who received TMZ might have 2,000 mutations in the recurrence." Further, new mutations were verified to carry known signatures of Temozolomide induced mutations. The research suggests that Temozolomide for the treatment of certain brain tumors should be thoroughly thought. Unjudicious usage of Temozolomide might lower the prognosis of the patients further, or increase their burden. Further understanding of the mechanisms of Temozolomide induced mutations and novel combination approaches could be promising.
Oligodendrogliomas are generally felt to be incurable using current treatments. However compared to the more common astrocytomas, they are slowly growing with prolonged survival. In one series, median survival times for oligodendrogliomas were 11.6 years for grade II and 3.5 years for grade III.
However, such figures can be misleading since they do not factor in the types of treatment nor the genetic signature of the tumors. A recent study analyzed survival based on chromosomal deletions and the effects of radiation or chemotherapy as treatment, with the following results (both low-grade and anaplastic oligodendrogliomas): 1p/19q deletion with radiation = 121 months (mean), 1p/19q deletion with chemotherapy = over 160 months (mean not yet reached), no 1p/19q deletion with radiation = 58 months (mean), and no 1p/19q deletion with chemotherapy = 75 months (mean). Another study divided anaplastic oligodendrogliomas into the following four clinically relevant groups of histology with the following results: combined 1p/19q loss = median survival was >123 months (not yet reached), 1p loss only = median survival was 71 months, 1p intact with TP53 mutation = median survival 71 months, and 1p intact with no TP53 mutation = median survival was 16 months.
Because of the indolent nature of these tumors and the potential morbidity associated with neurosurgery, chemotherapy and radiation therapy, most neurooncologists will initially pursue a course of watchful waiting and treat patients symptomatically. Symptomatic treatment often includes the use of anticonvulsants for seizures and steroids for brain swelling. PCV chemotherapy (Procarbazine, CCNU and Vincristine) has been shown to be effective and was the most commonly used chemotherapy regimen used for treating anaplastic oligodendrogliomas, but is now being superseded by a newer drug: Temozolomide. Temozolomide is a common chemotherapeutic drug to which oligodendrogliomas appear to be quite sensitive. It is often used as a first line therapy, especially because of its relatively mild side effects when compared to other chemotherapeutic drugs.
Nevertheless, a retrospective study on 1054 patients with anaplastic oligodendroglioma, presented during the 2009 ASCO Annual Meeting, suggests that PCV therapy may be superior in efficacy to the newer temozolomide therapy. Median time to progression for patients with 1p19q co-deletion was longer following PCV alone (7.6 years) than with temozolomide alone (3.3 years); median overall survival was also longer with PCV treatment versus temozolomide treatment (not reached, vs. 7.1 years).
The standard dosing schedule of temozolomide is 5 consecutive days of daily dosing during 28-day cycles. However, different dosing schedules may produce better results, such as continuous daily dosing using lower amounts of drug (e.g. 21-day dosing during 28-day cycles). As an example of an altered dosing schedule, promising results have been shown using lower daily doses on each day for 7 weeks, followed by a 4-week off periods. Regarding the duration of dosing, for oligodendrogliomas the duration prescribed by oncologists varies considerably and seems to range from 6 cycles to over 32 cycles (i.e. over 3 years). In one study, researchers compared patients who received temozolomide for at least 12 months on the 5/28 day cycle, dividing such patients into two groups: "short term" patients receiving temozolomide for 12-18 cycles and those "long term" patients receiving 19 or more cycles (range was 19 to 32 cycles). Researchers found that there was a statistically significant advantage for "long term" treatment (median progression free survival for "short term" patients was 95 weeks (follow up of 73 weeks), but for "long term" patients the median progression free survival was not yet reached (follow up of 134 weeks)).
Because of their diffusely infiltrating nature, oligodendrogliomas cannot be completely resected and are not curable by surgical excision. If the tumor mass compresses adjacent brain structures, a neurosurgeon will typically remove as much of the tumor as he or she can without damaging other critical, healthy brain structures. Surgery may be followed up by chemotherapy, radiation, or a mix of both, but recent studies suggest that radiation does not improve overall survival (even when age, clinical data, histological grading, and type of surgery are considered). However, a recent long-term study does affirm that radiation combined with adjuvant chemotherapy is significantly more efficacious for anaplastic oligodendroglioma patients with 1p 19q co-deleted tumors and has become the new standard of care. However, it is possible that radiotherapy may prolong the overall time to progression for non-deleted tumors.
Oligodendrogliomas, like all other infiltrating gliomas, have a very high (almost uniform) rate of recurrence and gradually increase in grade over time. Recurrent tumors are generally treated with more aggressive chemotherapy and radiation therapy. Recently, stereotactic surgery has proven successful in treating small tumors that have been diagnosed early.
Long-term survival is reported in a minority of patients. With aggressive treatment and close monitoring, it is possible to outlive the typical life expectancies for both low grade and high grade oligodendrogliomas. Westergaard's
study (1997) showed that patients younger than 20 years had a median survival of 17.5 years. Another study shows a 34% survival rate after 20 years. However, as discussed above, such figures can be misleading since they do not factor in the types of treatment nor the genetic signature of the tumors. Additionally, such historic data loses significance due to the relatively long survival of patients (compared to other types of brain tumors) and the introduction of newer treatment options over time.
For recurrent high-grade glioblastoma, recent studies have taken advantage of angiogenic blockers such as bevacizumab in combination with conventional chemotherapy, with encouraging results.
The age-standardized 5-year relative survival rate is 23.6%. Patients with this tumor are 46 times more likely to die than matched members of the general population. It is important to note that prognosis across age groups is different especially during the first three years post-diagnosis. When the elderly population is compared with young adults, the excess hazard ratio (a hazard ratio that is corrected for differences in mortality across age groups) decreases from 10.15 to 1.85 at 1 to 3 years, meaning that the elderly population are much more likely to die in the first year post-diagnosis when compared to young adults (aged 15 to 40), but after three years, this difference is reduced markedly.
Typical median survival for anaplastic astrocytoma is 2–3 years. Secondary progression to glioblastoma multiforme is common. Radiation, younger age, female sex, treatment after 2000, and surgery were associated with improved survival in AA patients.
Even after surgery, an oligoastrocytoma will often recur. The treatment for a recurring brain tumor may include surgical resection, chemo and radiation therapy. Survival time of this brain tumor varies - younger age and low-grade initial diagnosis are factors in improved survival time.
Children with PXA may experience seizures as a symptom of their disease. However, any person undergoing brain surgery is at risk of developing epileptic seizures. Medication is administered to minimize or prevent seizure activity. Additionally, after surgery, parents should be informed of the risk of seizures, and educated on what to do in the event of a seizure.
With any brain surgery, there is also a risk of brain damage.
With treatment, pleomorphic xanthoastrocytomas are associated with a high rate of cure.
- Grade II pleomorphic xanthoastrocytomas are known to progress towards grade II tumors, which are more likely to recur after surgical removal.
- Grade III anaplastic pleomorphic xanthoastrocytomas may evolve and show signs of anaplasia, according to evidence in the medical literature.
Oligo Nation is a 501(c)(3) organization which raises funds for research into a cure for oligodendroglioma. It was founded by a family whose two sons were both diagnosed with oligodendroglioma within two years of each other. As of 2017 Oligo Nation has raised more than $2 million and funded multiple research projects, including two immunotherapy clinical trials, one of which focuses on anti-CD47 approaches. In October 2016 Oligo Nation organized a summit at Stanford bringing together 18 researchers to plan a research strategy.
Definitive treatment for ganglioglioma requires gross total surgical resection, and a good prognosis is generally expected when this is achieved. However, indistinct tumor margins and the desire to preserve normal spinal cord tissue, motor and sensory function may preclude complete resection of tumor. According to a series by Lang et al., reviewing several patients with resected spinal cord ganglioglioma, the 5- and 10-year survival rates after total resection were 89% and 83%, respectively. In that study, patients with spinal cord ganglioglioma had a 3.5-fold higher relative risk of tumor recurrence compared to patients with supratentorial ganglioglioma. It has been recognized that postoperative results correlate closely with preoperative neurological status as well as the ability to achieve complete resection.
With the exception of WHO grade III anaplastic ganglioglioma, radiation therapy is generally regarded to have no role in the treatment of ganglioglioma. In fact, radiation therapy may induce malignant transformation of a recurrent ganglioglioma several years later. Adjuvant chemotherapy is also typically reserved for anaplastic ganglioglioma, but has been used anecdotally in partially resected low grade spinal cord gangliogliomas which show evidence of disease progression.
If resected, the surgeon will remove as much of this tumor as possible, without disturbing eloquent regions of the brain (speech/motor cortex) and other critical brain structure. Thereafter, treatment may include chemotherapy and radiation therapy of doses and types ranging based upon the patient's needs. Subsequent MRI examination are often necessary to monitor the resection cavity.
Supportive treatment focuses on relieving symptoms and improving the patient’s
neurologic function. The primary supportive agents are anticonvulsants and
corticosteroids.
- Historically, around 90% of patients with glioblastoma underwent anticonvulsant treatment, although it has been estimated that only approximately 40% of patients required this treatment. Recently, it has been recommended that neurosurgeons not administer anticonvulsants prophylactically, and should wait until a seizure occurs before prescribing this medication. Those receiving phenytoin concurrent with radiation may have serious skin reactions such as erythema multiforme and Stevens–Johnson syndrome.
- Corticosteroids, usually dexamethasone given 4 to 8 mg every 4 to 6 h, can reduce peritumoral edema (through rearrangement of the blood–brain barrier), diminishing mass effect and lowering intracranial pressure, with a decrease in headache or drowsiness.
Chemotherapy is the preferred secondary treatment after resection. The treatment kills astroblastoma cells left behind after surgery and induces a non-dividing, benign state for remaining tumor cells. Normally, chemotherapy is not recommended until the second required resection, implying that the astroblastoma is a high-grade tumor continuing to recur every few months. A standard chemotherapy protocol starts with two rounds of nimustine hydrochoride (ACNU), etoposide, vincristine, and interferon-beta. The patient undergoes a strict drug regimen until another surgery is required. By the third surgery, should recurrence in the astroblastoma occur, a six-round program of ifosfamide, cisplatin, and etoposide will "shock" the patient's system to the point where recurrence halts. Unfortunately, chemotherapy may not always be successful with patients requiring further resection of the tumor, since the tumor cell begins to show superior vasculature and a strong likelihood of compromising a patient's well-being. Oral ingestion of temozolomide for at-home bedside use may be preferred by the patient.
Use of telomerase inhibitors such as Imetelstat seem to have very low toxicity compared to other chemotherapy. The only known side effect of most telomerase inhibitors is dose-induced neutropenia. Neuropsychological deficits can result from resection, chemotherapy, and radiation, as well as endocrinopathies. Additionally, an increase in gastrointestinal complications has been observed in survivors of pediatric cancers.
Cancer immunotherapy is being actively studied. For malignant gliomas no therapy has been shown to improve life expectancy as of 2015.
At this point, no literature has indicated whether environmental factors increase the likelihood of astroblastoma. Although cancer in general is caused by a variety of external factors, including carcinogens, dangerous chemicals, and viral infections, astroblastoma research has not even attempted to classify incidence in this regard. The next few decades will aid in this understanding.
Palliative treatment usually is conducted to improve quality of life and to achieve a longer survival time. It includes surgery, radiation therapy, and chemotherapy. A maximally feasible resection with maximal tumor-free margins is usually performed along with external beam radiation and chemotherapy. Gross total resection of tumor is associated with a better prognosis.
hTERT and yH2AX are crucial markers for prognosis and response to therapy. High hTERT and low yH2AX expression is associated with poor response to therapy. Patients with both high or low expression of these markers make up the moderate response groups.
For low grade astrocytomas, removal of the tumor will generally allow functional survival for many years. In some reports, the five-year survival has been over 90% with well resected tumors. Indeed, broad intervention of low grade conditions is a contested matter. In particular, pilocytic astrocytomas are commonly indolent bodies that may permit normal neurologic function. However, left unattended these tumors may eventually undergo neoplastic transformation. To date, complete resection of high grade astrocytomas is impossible because of the diffuse infiltration of tumor cells into normal parenchyma. Thus, high grade astrocytomas inevitably recur after initial surgery or therapy, and are usually treated similarly as the initial tumor. Despite decades of therapeutic research, curative intervention is still nonexistent for high grade astrocytomas; patient care ultimately focuses on palliative management.
Led by Prof. Nori Kasahara, researchers from USC, who are now at UCLA, reported in 2001 the first successful example of applying the use of retroviral replicating vectors towards transducing cell lines derived from solid tumors. Building on this initial work, the researchers applied the technology to "in vivo" models of cancer and in 2005 reported a long-term survival benefit in an experimental brain tumor animal model. Subsequently, in preparation for human clinical trials, this technology was further developed by Tocagen (a pharmaceutical company primarily focused on brain cancer treatments) as a combination treatment (Toca 511 & Toca FC). This has been under investigation since 2010 in a Phase I/II clinical trial for the potential treatment of recurrent high-grade glioma including glioblastoma multiforme (GBM) and anaplastic astrocytoma. No results have yet been published.
Recent focus has been to reduce therapy for low and intermediate risk neuroblastoma while maintaining survival rates at 90%. A study of 467 intermediate risk patients enrolled in A3961 from 1997 to 2005 confirmed the hypothesis that therapy could be successfully reduced for this risk group. Those with favorable characteristics (tumor grade and response) received four cycles of chemotherapy, and those with unfavorable characteristics received eight cycles, with three-year event free survival and overall survival stable at 90% for the entire cohort. Future plans are to intensify treatment for those patients with aberration of 1p36 or 11q23 chromosomes as well as for those who lack early response to treatment.
By contrast, focus the past 20 years or more has been to intensify treatment for high-risk neuroblastoma. Chemotherapy induction variations, timing of surgery, stem cell transplant regimens, various delivery schemes for radiation, and use of monoclonal antibodies and retinoids to treat minimal residual disease continue to be examined. Recent phase III clinical trials with randomization have been carried out to answer these questions to improve survival of high-risk disease:
When the lesion is localized, it is generally curable. However, long-term survival for children with advanced disease older than 18 months of age is poor despite aggressive multimodal therapy (intensive chemotherapy, surgery, radiation therapy, stem cell transplant, differentiation agent isotretinoin also called 13-"cis"-retinoic acid, and frequently immunotherapy with anti-GD2 monoclonal antibody therapy).
Biologic and genetic characteristics have been identified, which, when added to classic clinical staging, has allowed patient assignment to risk groups for planning treatment intensity. These criteria include the age of the patient, extent of disease spread, microscopic appearance, and genetic features including DNA ploidy and N-myc oncogene amplification (N-myc regulates microRNAs), into low, intermediate, and high risk disease. A recent biology study (COG ANBL00B1) analyzed 2687 neuroblastoma patients and the spectrum of risk assignment was determined: 37% of neuroblastoma cases are low risk, 18% are intermediate risk, and 45% are high risk. (There is some evidence that the high- and low-risk types are caused by different mechanisms, and are not merely two different degrees of expression of the same mechanism.)
The therapies for these different risk categories are very different.
- Low-risk disease can frequently be observed without any treatment at all or cured with surgery alone.
- Intermediate-risk disease is treated with surgery and chemotherapy.
- High-risk neuroblastoma is treated with intensive chemotherapy, surgery, radiation therapy, bone marrow / hematopoietic stem cell transplantation, biological-based therapy with 13-"cis"-retinoic acid (isotretinoin or Accutane) and antibody therapy usually administered with the cytokines GM-CSF and IL-2.
With current treatments, patients with low and intermediate risk disease have an excellent prognosis with cure rates above 90% for low risk and 70–90% for intermediate risk. In contrast, therapy for high-risk neuroblastoma the past two decades resulted in cures only about 30% of the time. The addition of antibody therapy has raised survival rates for high-risk disease significantly. In March 2009 an early analysis of a Children's Oncology Group (COG) study with 226 high-risk patients showed that two years after stem cell transplant 66% of the group randomized to receive ch14.18 antibody with GM-CSF and IL-2 were alive and disease-free compared to only 46% in the group that did not receive the antibody. The randomization was stopped so all patients enrolling on the trial will receive the antibody therapy.
Chemotherapy agents used in combination have been found to be effective against neuroblastoma. Agents commonly used in induction and for stem cell transplant conditioning are platinum compounds (cisplatin, carboplatin), alkylating agents (cyclophosphamide, ifosfamide, melphalan), topoisomerase II inhibitor (etoposide), anthracycline antibiotics (doxorubicin) and vinca alkaloids (vincristine). Some newer regimens include topoisomerase I inhibitors (topotecan and irinotecan) in induction which have been found to be effective against recurrent disease.
Likely, current chemotherapies are not effective. Antiprogestin agents have been used, but with variable results. A 2007 study of whether hydroxyurea has the capacity to shrink unresectable or recurrent meningiomas is being further evaluated.
There are no precise guidelines because the exact cause of astrocytoma is not known.
Radiation therapy may include photon-beam or proton-beam treatment, or fractionated external beam radiation. Radiosurgery may be used in lieu of surgery in small tumors located away from critical structures. Fractionated external-beam radiation also can be used as primary treatment for tumors that are surgically unresectable or, for patients who are inoperable for medical reasons.
Radiation therapy often is considered for WHO grade I meningiomas after subtotal (incomplete) tumor resections. The clinical decision to irradiate after a subtotal resection is somewhat controversial, as no class I randomized, controlled trials exist on the subject. Numerous retrospective studies, however, have suggested strongly that the addition of postoperative radiation to incomplete resections improves both progression-free survival (i.e. prevents tumor recurrence) and improves overall survival.
In the case of a grade III meningioma, the current standard of care involves postoperative radiation treatment regardless of the degree of surgical resection. This is due to the proportionally higher rate of local recurrence for these higher-grade tumors. Grade II tumors may behave variably and there is no standard of whether to give radiotherapy following a gross total resection. Subtotally resected grade II tumors should be radiated.