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According to a Dutch source juvenile pilocytic astrocytoma occurs at a rate of 2 in 100,000 people. Most affected are children ages 5–14 years. According to the National Cancer Institute more than 80% of astrocytomas located in the cerebellum are low grade (pilocytic grade I) and often cystic; most of the remainder are diffuse grade II astrocytomas.
Tumors of the optic pathway account for 3.6-6% of pediatric brain tumors, 60% of which are juvenile pilocytic astrocytomas. Astrocytomas account for 50% of pediatric primary central nervous system tumors. About 80-85% of cerebellar astrocytomas are juvenile pilocytic astrocytomas.
Recent genetic studies of pilocytic astrocytomas show that some sporadic cases have gain in chromosome 7q34 involving the BRAF locus.
Children with cerebellar pilocytic astrocytoma may experience side effects related to the tumor itself depending on the location and related to the treatment. Strabismus.
- Symptoms related to increased pressure in the brain often disappear after surgical removal of the tumor.
- Effects on coordination and balance improved and might progressively (to completely) disappear as recovery progresses.
- Steroid-treatment is often used to control tissue swelling that may occur pre- and post-operatively.
- Children Diagnosed can also suffer long term side effects due to the type of treatment they may receive.
Two related drugs have been shown to shrink or stabilize subependymal giant cell tumors: rapamycin and everolimus. These both belong to the mTOR inhibitor class of immunosuppressants, and are both contraindicated in patients with severe infections.
Rapamycin showed efficacy in five cases of SEGA in TSC patients, shrinking their tumor volumes by an average of 65%. However, after the drug was stopped, the tumors regrew.
Everolimus, which has a similar structure as rapamycin, but with slightly increased bioavailability and shorter half-life, was studied in 28 patients with SEGA. There was a significant reduction in SEGA size in 75% of the patients, and a mild improvement in their seizures. Everolimus was approved for the treatment of SEGA by the US Food and Drug Administration (FDA) in October, 2010.
Chemotherapy is often used as part of treatment. Evidence of benefit, however, is not clear as of 2013. A few different chemotherapeutic regimens for medulloblastoma are used, but most involve a combination of lomustine, cisplatin, carboplatin, vincristine, or cyclophosphamide. In younger patients (less than 3–4 years of age), chemotherapy can delay, or in some cases possibly even eliminate, the need for radiotherapy. However, both chemotherapy and radiotherapy often have long-term toxicity effects, including delays in physical and cognitive development, higher risk of second cancers, and increased cardiac disease risks.
Array-based karyotyping of 260 medulloblastomas by Pfister S, "et al." resulted in the following clinical subgroups based on cytogenetic profiles:
- Poor prognosis: gain of 6q or amplification of MYC or MYCN
- Intermediate: gain of 17q or an i(17q) without gain of 6q or amplification of MYC or MYCN
- Excellent prognosis: 6q and 17q balanced or 6q deletion
Transcriptional profiling shows the existence of four main subgroups (Wnt, Shh, Group 3, and Group 4).
- Very good prognosis: WNT group," CTNNB"1 mutation
- Infants good prognosis, others intermediate: SHH group, "PTCH1/SMO/SUFU" mutation, "GLI2" amplification, or "MYCN" amplification
- Poor prognosis: Group 3, "MYC" amplification, photoreceptor/GABAergic gene expression
- Intermediate prognosis: Group 4, gene expression of neuronal/glutamatergic, "CDK6" amplification, "MYCN" amplification
A NIH Consensus Conference report in 1999 recommends that any SEGA that is growing or causing symptoms should be surgically removed. Tumors are also removed in cases where a patient is suffering from a high seizure burden. If a tumor is rapidly growing or causing symptoms of hydrocephalus, deferring surgery may lead to vision loss, need for ventricular shunt, and ultimately death. Total removal of the tumor is curative.
Surgery to remove intraventricular tumors also carries risks of complications or death. Potential complications include transient memory impairment, hemiparesis, infection, chronic ventriculoperitoneal shunt placement, stroke, and death.
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.
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.
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.
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.
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.
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 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.
Treatment options include surgery, radiotherapy, radiosurgery, and chemotherapy.
The infiltrating growth of microscopic tentacles in fibrillary astrocytomas makes complete surgical removal difficult or impossible without injuring brain tissue needed for normal neurological function. However, surgery can still reduce or control tumor size. Possible side effects of surgical intervention include brain swelling, which can be treated with steroids, and epileptic seizures. Complete surgical excision of low grade tumors is associated with a good prognosis. However, the tumor may recur if the resection is incomplete, in which case further surgery or the use of other therapies may be required.
Standard radiotherapy for fibrillary astrocytoma requires from ten to thirty sessions, depending on the sub-type of the tumor, and may sometimes be performed after surgical resection to improve outcomes and survival rates. Side effects include the possibility of local inflammation, leading to headaches, which can be treated with oral medication. Radiosurgery uses computer modelling to focus minimal radiation doses at the exact location of the tumor, while minimizing the dose to the surrounding healthy brain tissue. Radiosurgery may be a complementary treatment after regular surgery, or it may represent the primary treatment technique.
Although chemotherapy for fibrillary astrocytoma improve overall survival, it is effective only in about 20% of cases. Researchers are currently investigating a number of promising new treatment techniques including gene therapy, immunotherapy, and novel chemotherapies.
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.
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.
Dr. Sidney Farber, founder of Dana-Farber Cancer Institute, and his colleagues achieved the first remissions in Wilms tumor in the 1950s. By employing the antibiotic actinomycin D in addition to surgery and radiation therapy, they boosted cure rates from 40 to 89 percent.
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.
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.
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.
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.