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Chemotherapy is typically limited to patients with recurrent central neurocytoma. The course of chemotherapy used for CNC is one of two platinum-based regimes. The two regimes are:
- Carboplatin + VP-16 + ifosfamide
- cisplatin + VP-16 + cyclophosphamide
Because chemotherapy is used in rare cases there is still information to be gathered as to the efficacy of chemotherapy to treat benign CNC. Therefore, recommendations must be viewed as limited and preliminary.
There is not much evidence supporting the claim that radiotherapy is a beneficial and effective means of treatment. Typically, radiotherapy is used postoperatively in respect to whether or not a partial or complete excision of the tumor has been accomplished. The histopathological features of CNC, neuronal differentiation, low mitotic activity, absence of vascular endothelial proliferation, and tumor necrosis, suggest that the tumor may be resistant to ionizing radiation. However, when radiotherapy is used, whole brain or involved-field treatment is given. This method utilizes a standard fractionation schedule and a total tumor dose of 50-55 Gy. Gamma knife surgery is a form of radiotherapy, more specifically radiosurgery that uses beams of gamma rays to deliver a certain dosage of radiation to the tumor. Gamma knife surgery is incredibly effective at treating neurocytoma and maintaining tumor control after the procedure when a complete excision has been performed. Some studies have found that the success rate of tumor control is around 90% after the first five years and 80% after the first ten years. Gamma knife surgery is the most recorded form of radiotherapy performed to treat remnants of the CNC tumor after surgery.
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 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.
Patients undergoing chemotherapy are administered drugs designed to kill tumor cells. Although chemotherapy may improve overall survival in patients with the most malignant primary brain tumors, it does so in only about 20 percent of patients. Chemotherapy is often used in young children instead of radiation, as radiation may have negative effects on the developing brain. The decision to prescribe this treatment is based on a patient's overall health, type of tumor, and extent of the cancer. The toxicity and many side effects of the drugs, and the uncertain outcome of chemotherapy in brain tumors puts this treatment further down the line of treatment options with surgery and radiation therapy preferred.
UCLA Neuro-Oncology publishes real-time survival data for patients with a diagnosis of glioblastoma multiforme. They are the only institution in the United States that displays how brain tumor patients are performing on current therapies. They also show a listing of chemotherapy agents used to treat high-grade glioma tumors.
The goal of radiation therapy is to kill tumor cells while leaving normal brain tissue unharmed. In standard external beam radiation therapy, multiple treatments of standard-dose "fractions" of radiation are applied to the brain. This process is repeated for a total of 10 to 30 treatments, depending on the type of tumor. This additional treatment provides some patients with improved outcomes and longer survival rates.
Radiosurgery is a treatment method that uses computerized calculations to focus radiation at the site of the tumor while minimizing the radiation dose to the surrounding brain. Radiosurgery may be an adjunct to other treatments, or it may represent the primary treatment technique for some tumors. Forms used include stereotactic radiosurgery, such as Gamma knife, Cyberknife or Novalis Tx radiosurgery.
Radiotherapy may be used following, or in some cases in place of, resection of the tumor. Forms of radiotherapy used for brain cancer include external beam radiation therapy, the most common, and brachytherapy and proton therapy, the last especially used for children.
Radiotherapy is the most common treatment for secondary brain tumors. The amount of radiotherapy depends on the size of the area of the brain affected by cancer. Conventional external beam "whole-brain radiotherapy treatment" (WBRT) or "whole-brain irradiation" may be suggested if there is a risk that other secondary tumors will develop in the future. Stereotactic radiotherapy is usually recommended in cases involving fewer than three small secondary brain tumors.
People who receive stereotactic radiosurgery (SRS) and whole-brain radiation therapy (WBRT) for the treatment of metastatic brain tumors have more than twice the risk of developing learning and memory problems than those treated with SRS alone.
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.
Radiation therapy selectively kills astroblastoma cells while leaving surrounding normal brain tissue unharmed. The use of radiation therapy after an astroblastoma excision has variable results. Conventional external beam radiation has both positive and negative effects on patients, but it is not recommended at this point to treat all types. All in all, the radiosensitivity of astroblastoma to therapy remains unclear, since some research advocate its effectiveness while others diminish the effects. Future studies must be done on patients with both total excision and sub-excision of the tumor to accurately assess whether radiation benefits patients under different circumstances.
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.
Around 50% of the AT/RTs will transiently respond, but chemotherapy by itself is rarely curative. No standard treatment for AT/RT is known. Various chemotherapeutic agents have been used against AT/RTs, which are also used against other CNS tumors including cisplatinum, carboplatinum, cyclophosphamide, vincristine, and etoposide. Some chemotherapy regimens are listed below:
- CCG clinical trial CCG-9921 was activated in 1993 and published its results in 2005. The proposed treatments did not have different outcomes and were not an improvement on prior treatments. Geyer published a review of chemotherapy on 299 infants with CNS tumors that evaluated response rate, event-free survival (EFS), and toxicity of two chemotherapeutic regimens for treatment of children younger than 36 months with malignant brain tumors. Patients were randomly assigned to one of two regimens of induction chemotherapy (vincristine, cisplatin, cyclophosphamide, and etoposide v vincristine, carboplatin, ifosfamide, and etoposide). Intensified induction chemotherapy resulted in a high response rate of malignant brain tumors in infants. Survival was comparable to that of previous studies, and most patients who survived did not receive radiation therapy.
- Sarcoma protocols. There has been at least one report in the literature of malignant rhabdoid tumors of the CNS being treated in as a high-grade intracranial sarcoma. These three cases were treated with surgery, chemotherapy, radiotherapy and triple intrathecal chemotherapy similar to the Intergroup Rhabdomyosarcoma Study III guidelines.
- Intrathecal protocols. One of the difficulties with brain and spinal tumors is that the blood brain barrier needs to be crossed so that the drug can get to the tumor. One mechanism to deliver the drug is through a device called an Ommaya reservoir. This is a device which shares some characteristics with a shunt in which a tube a surgically placed in the fluid surrounding the brain and a bulb shaped reservoir attached to the tubing is placed under the skin of the scalp. When the child is to receive intrathecal chemotherapy, the drug is administered into this bulb reservoir. At other times intrathecal chemotherapeutic agents are delivered through a lumbar puncture (spinal tap). A current Pediatric Brain Tumor Consortium Protocol uses intrathecal mafosfamide, a pre-activated cyclophosphamide derivative, in addition to other modalities to try to effect this tumor.
- High dose chemotherapy with stem cell rescue. This therapy uses chemotherapy at doses high enough to completely suppress the bone marrow. Prior to instituting this therapy, the child has a central line placed and stem cells are gathered. After therapy these cells are given back to the child to regrow the bone marrow. Stem cell rescue or autologous bone marrow transplantation, was initially thought to be of benefit to a wide group of patients, but has declined over the history of chemotherapy protocols.
Most studies show no benefit from the addition of chemotherapy. However, a large clinical trial of 575 participants randomized to standard radiation versus radiation plus temozolomide chemotherapy showed that the group receiving temozolomide survived a median of 14.6 months as opposed to 12.1 months for the group receiving radiation alone. This treatment regime is now standard for most cases of glioblastoma where the person is not enrolled in a clinical trial. Temozolomide seems to work by sensitizing the tumor cells to radiation.
High doses of temozolomide in high-grade gliomas yield low toxicity, but the results are comparable to the standard doses.
Antiangiogenic therapy with medications such as bevacizumab control symptoms but do not affect overall survival.
The traditional practice for childhood brain tumors has been to use chemotherapy and to defer radiation therapy until a child is older than three years. This strategy is based upon observations that children under three have significant long-term complications as a result of brain irradiation. However, the long-term outcomes of AT/RT are so poor that some protocols call for upfront radiation therapy, often in spite of young age.
The dose and volume of radiation had not been standardized, but radiation does appear to improve survival. The use of radiation has been limited in children younger than three because of the risk of severe neurocognitive deficits. Protocols using conformal, local radiation in the young child are used to try to cure this tumor.
External beam (conformal) radiation uses several beams that intersect at the tumor location; the normal brain tissue receives less radiation and cognitive function is thereby less affected.
Proton beam radiation was only offered at Massachusetts General Hospital in Boston and at Loma Linda, California, as of 2002. Since 2003, three or four more proton therapy centers have opened in the United States. St. Jude Children's Research Hospital is in the process of building one at their Memphis, Tennessee, location. Some centers have since opened in Europe. (Germany, Switzerland, and France).
Because ganglioneuromas are benign, treatment may not be necessary, as it would expose patients to more risk than leaving it alone. If there are symptoms or major physical deformity, treatment usually consists of surgery to remove the tumor.
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.
Treatment for neurofibrosarcoma is similar to that of other cancers.
Surgery is an option; the removal of the tumor along with surrounding tissue may be vital for the patient’s survival. For discrete, localized tumors, surgery is often followed by radiation therapy of the excised area to reduce the chance of recurrence.
For patients suffering from neurofibrosarcomas in an extremity, if the tumor is vascularized (has its own blood supply) and has many nerves going through it and/or around it, amputation of the extremity may be necessary. Some surgeons argue that amputation should be the procedure of choice when possible, due to the increased chance of a better quality of life. Otherwise, surgeons may opt for a limb-saving treatment, by removing less of the surrounding tissue or part of the bone, which is replaced by a metal rod or grafts.
Radiation will also be used in conjunction with surgery, especially if the limb was not amputated. Radiation is rarely used as a sole treatment.
In some instances, the oncologist may choose chemotherapy drugs when treating a patient with neurofibrosarcoma, usually in conjunction with surgery. Patients taking chemotherapy must be prepared for the side effects that come with any other chemotherapy treatment, such as; hair loss, lethargy, weakness, etc.
Most treatments involve some combination of surgery and chemotherapy. Treatment with cisplatin, etoposide, and bleomycin has been described.
Before modern chemotherapy, this type of neoplasm was highly lethal, but the prognosis has significantly improved since.
When endodermal sinus tumors are treated promptly with surgery and chemotherapy, fatal outcomes are exceedingly rare.
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.
Chemotherapy with topotecan and cyclophosphamide is frequently used in refractory setting and after relapse.
Most ganglioneuromas are noncancerous, thus expected outcome is usually good. However, a ganglioneuroma may become cancerous and spread to other areas, or it may regrow after removal.
If the tumor has been present for a long time and has pressed on the spinal cord or caused other symptoms, it may have caused irreversible damage that cannot be corrected with the surgical removal of the tumor. Compression of the spinal cord may result in paralysis, especially if the cause is not detected promptly.
General treatment regimens have not changed much in the past 30 years, in part due to the lack of randomized clinical trials. Surgery is the treatment of choice if the tumor is determined to be resectable. Curettage is a commonly used technique. The situation is complicated in a patient with a pathological fracture. It may be best to immobilize the affected limb and wait for the fracture to heal before performing surgery.
Patients with tumors that are not amenable to surgery are treated with radiation therapy. However caution is employed since a majority of recurrent tumors with transformations to the malignant sarcoma phenotype have been in patients receiving radiotherapy for their primary benign lesion. Pharmacotherapy for GCTOB, includes bisphosphonates such as Zoledronate, which are thought to induce apoptosis in the MNGC fraction, preventing tumor-induced osteolysis. Indeed, "in vitro" studies have shown zolidronate to be effective in killing osteoclast-like cells. More recently, humanized monoclonal antibodies such as Denosumab targeting the RANK ligand have been employed in treatment of GCTOB in a phase II study. This is based on the notion that increased expression of RANK-ligands by stromal cells plays a role in tumor pathogenesis.
The Stehlin Foundation currently offers DSRCT patients the opportunity to send samples of their tumors free of charge for testing. Research scientists are growing the samples on nude mice and testing various chemical agents to find which are most effective against the individual's tumor.
Patients with advanced DSRCT may qualify to participate in clinical trials that are researching new drugs to treat the disease.
The primary method for treatment is surgical, not medical. Radiation and chemotherapy are not needed for benign lesions and are not effective for malignant lesions.
Benign granular cell tumors have a recurrence rate of 2% to 8% when resection margins are deemed clear of tumor infiltration. When the resection margins of a benign granular cell tumor are positive for tumor infiltration the recurrence rate is increased to 20%. Malignant lesions are aggressive and difficult to eradicate with surgery and have a recurrence rate of 32%.
Cimetidine works by slowing tumor growth; it is a histamine blocker that maintains the body’s immune response which aids in the killing of tumor cells. Cimetidine has not been proven to efficiently resolve tumors completely.
Cisplatin is a chemotherapy drug that is injected into the tumor itself; this drug is commonly used along with surgical removal. That being said, this drug has been shown to resolve tumors with or without surgical removal for at least 2 years.
Epithelioid sarcoma (especially advanced stage, recurrent, or metastasized disease) has been shown to be resistant to traditional cancer therapies, necessitating further exploration of novel treatment methods and techniques. Because of the relatively poor response of epithelioid sarcoma to traditional cancer treatments (surgery, chemotherapy, and radiation), new treatment strategies are being looked to.