Neurogliomas, referred to as gliomas, are tumors that occur in the neural ectoderm. There are two types of tumors occurring in the neural ectoderm, one formed by mesenchymal cells, called gliomas, and the other formed by parenchymal cells, called neuronal tumors. Because these two types of tumors cannot be completely distinguished from each other pathologically and morphologically, and because gliomas originating from mesenchymal cells are much more common than neuronal tumors originating from parenchymal cells, neuronal tumors are included in gliomas, which are collectively referred to as gliomas. Gliomas are tumors that occur in the neural ectoderm, so they are also called neuroectodermal tumors or neuroepithelial tumors. Tumors originate from neural mesenchymal cells, i.e., neuroglia, the ventricular canal membrane, choroid plexus epithelium, and neuroparenchymal cells, i.e., neurons. Most tumors originate from different types of glia, but based on the histogenetic origin and similar biological characteristics, the various review tumor diseases that occur in the neural ectoderm are generally referred to as gliomas . There are many ways to classify gliomas, and clinicians tend to use the Kernohan classification, which is relatively simple to classify. Of the various types of gliomas, astrocytomas are the most prevalent, followed by glioblastomas and then, in descending order, medulloblastomas, ventricular meningiomas, oligodendrogliomas, pineal tumors, mixed gliomas, choroid plexus papillomas, unclassified gliomas, and neuronal neoplasms. Each type of glioma has a different site of occurrence. For example, astrocytomas are found in the cerebral hemispheres in adults and in the cerebellum in children; glioblastomas are almost always found in the cerebral hemispheres; medulloblastomas are found in the earthy portion of the cerebellum; ventricular meningiomas are most often seen in the fourth ventricle; and oligodendroglial tumors are found in most of the cerebral hemispheres. Gliomas are more common in men, especially in glioblastoma multiforme and medulloblastoma, which are significantly more common in men than in women. Glioblastomas of all types are most common in middle age, ventricular meningiomas in children and young adults, and medulloblastomas almost always occur in children. The location of gliomas is also related to age, e.g., astrocytomas and glioblastomas of the brain are most often seen in adults, and gliomas of the cerebellum (astrocytomas, medulloblastomas, and ventricular meningiomas) are most often seen in children. Most gliomas are slow-onset, with the time between the onset of symptoms and presentation at the doctor’s office usually ranging from weeks to months, and in a few cases, up to several years. The history is shorter for highly malignant and posterior cranial fossa tumors, and longer for more benign ones or those located in the quiet zone. Symptoms can worsen suddenly if the tumor has hemorrhage or cystic lesions, or even have a cerebrovascular disease-like course. The clinical symptoms of glioma can be divided into two aspects, one is the symptoms of increased intracranial pressure, such as headache, vomiting, vision loss, diplopia, psychiatric symptoms, etc.; the other is the focal symptoms produced by the tumor’s compression, infiltration, and destruction of brain tissues, which can be manifested as irritation symptoms such as limited epilepsy in early stage, and neurological deficit symptoms such as paralysis in later stage. The diagnosis of glioma is analyzed according to its biological characteristics, age, sex, prevalent site and clinical course. On the basis of history and physical signs, using auxiliary examinations such as electrophysiology, ultrasound, radionuclide, radiology and MRI, the localization correctness rate is almost 100%, and the qualitative diagnosis correctness rate can be more than 90%. [Clinical manifestations The course of glioma varies according to the type of pathology and location, and the time from the appearance of symptoms to the consultation is usually several weeks to several months, and a few of them can last for several years. The history of highly malignant and posterior cranial fossa tumors tends to be shorter, and the history of more benign tumors or tumors located in the so-called quiet zone tends to be longer. The progression of symptoms can be accelerated in tumors with hemorrhage or cyst formation, and in some cases may even resemble the progression of cerebrovascular disease. Symptoms are manifested in two main ways. One is increased intracranial pressure and other general symptoms, such as headache, vomiting, vision loss, diplopia, seizures and psychiatric symptoms. The other is local symptoms resulting from compression, infiltration, and destruction of brain tissue by the tumor, causing neurological deficits. Headache is mostly due to increased intracranial pressure. Tumor growth gradually increases intracranial pressure, which compresses and involves intracranial pain-sensitive structures such as blood vessels, dura mater and certain cranial nerves to produce headache. Most of the headaches are throbbing and swelling pains, mostly in the frontotemporal or occipital area, and the headache may be mainly on the affected side in the superficial tumor of one cerebral hemisphere, which is intermittent and occurs in the early morning, and then worsens with the development of the tumor. Vomiting is due to the stimulation of the medullary vomiting center or vagus nerve, which may not be preceded by nausea and is projectile. In children, the headache may be insignificant due to the separation of the cranial sutures, and the vomiting is more prominent due to the prevalence of tumors in the posterior cranial fossa. Increased intracranial pressure may produce optic papillary edema, and for a long time lead to secondary atrophy of the optic nerve and vision loss. Tumor compression of the optic nerve produces primary optic nerve atrophy, which also leads to vision loss. The abducens nerve is easily compressed and pulled, often leading to paralysis and diplopia. A proportion of patients with tumors have epilepsy, which can be an early symptom. Epilepsy begins in adulthood and is usually symptomatic, mostly due to brain tumors. The presence of a brain tumor should be considered in patients who cannot be easily controlled by medications or who have a change in the nature of the seizures. Epilepsy is common in tumors adjacent to the cortex and rare in those deep within. Limited epilepsy has localizing significance. Some tumors, especially those located in the frontal lobe, may gradually develop psychiatric symptoms, such as personality changes, apathy, decreased speech and activity, poor concentration, memory loss, lack of concern for things, and lack of neatness. The local symptoms are according to the location of the tumor, and the symptoms will be aggravated progressively. Especially malignant glioma grows faster, infiltrates and destroys the brain tissue, and the surrounding brain edema is obvious, so the local symptoms are more obvious and develop faster. In the early stage of intracerebroventricular tumors or tumors located in the quiet zone, there may be no local symptoms. Tumors in the brainstem and other important functional parts of the brain may have local symptoms in the early stage, and symptoms of increased intracranial pressure may appear only after a long time. In some tumors with slow development, symptoms of increased intracranial pressure often appear only in the late stage due to the compensatory effect. [edit this paragraph] Pathology Due to the gradual enlargement of the tumor, intracranial space-occupying lesions are formed, often accompanied by peripheral cerebral edema, and when the compensatory limit is exceeded, increased intracranial pressure occurs. When the tumor blocks the cerebrospinal fluid circulation or compresses the veins, resulting in obstruction of venous return, the increase in intracranial pressure is aggravated. The process can be accelerated by hemorrhage, necrosis and cyst formation within the tumor. When the increase in intracranial pressure reaches a critical point, there continues to be a small increase in intracranial volume, and the intracranial pressure will increase rapidly. If intracranial pressure monitoring is performed, when the pressure reaches 6.67-13.3kPa Hg, plateau waves appear, and the repeated appearance of plateau waves with a long duration is a clinical sign. When the intracranial pressure is equal to the arterial pressure, the cerebral blood vessels are paralyzed, the cerebral blood flow stops, the blood pressure drops, and the patient will die soon. When the tumor increases in size, the local intracranial pressure is the highest, and the pressure gradient between the intracranial cavities is generated, resulting in cerebral displacement, and cerebral hernia is formed when it is gradually aggravated. Tumors of the supratentorial cerebral hemispheres may herniate under the cerebral falx, and the cingulate gyrus shifts across the midline, resulting in wedge-shaped necrosis. The pericallosal artery can also be displaced by pressure, and in severe cases, cerebral infarction can occur in the supply area. More importantly, the cerebellar vermis herniation occurs when the medial sulcus of the temporal lobe is displaced to the posterior cranial fossa through the cerebellar vermis. The ipsilateral motor nerve is paralyzed by compression, the pupil is dilated, and the light response is absent. Compression of the cerebral peduncle in the midbrain produces contralateral hemiparesis. Sometimes the contralateral cerebral peduncle presses against the edge of the cerebellar vermis or the apophysis, producing ipsilateral hemiparesis. Compression of the posterior choroidal artery and posterior cerebral artery may also cause ischemic necrosis. Finally, compression of the brainstem may produce downward axial displacement, leading to infarction and hemorrhage in the midbrain and upper pontine. The patient is comatose, blood pressure rises, pulse is slow, respiration is deep and irregular, and de-cerebralization may occur. Eventually, respiration stops, blood pressure drops, and death occurs due to cardiac arrest. Tumor of posterior cranial fossa under the curtain may produce hernia of the foramen magnum occipitalis, and the cerebellar tonsils are displaced downward to herniate out of the foramen magnum occipitalis. In severe cases, the medulla oblongata ventrally presses on the anterior border of the foramen magnum. Supratentorial tumors can also be associated with occipital foramen magnum hernia. As a result of medullary ischemia, the patient becomes comatose, blood pressure rises, pulse is slow and strong, and respiration is deep and unplanned. Subsequently, respiration stops, blood pressure decreases, pulse is rapid and weak, and death occurs. [edit]Epidemiology Neurogliomas are the most common among various intracranial tumors. Among gliomas astrocytomas are the most common, followed by glioblastoma multiforme, and ventricular meningiomas take the third place. According to the statistics of Xuanwu Hospital in Beijing and Affiliated Hospital of Tianjin Medical College, among 2573 cases of gliomas, 39.1%, 25.8% and 18.2% were found respectively. Sex was more common in males, especially in glioblastoma multiforme and medulloblastoma, which were significantly more common in males than females. Most of the gliomas were found in the age group of 20 to 50 years old, with 30 to 40 years old as the highest peak, and another small peak was found in children around 10 years old. Each type of glioma has its own age of prevalence, such as astrocytomas occurring in the prime of life, glioblastoma multiforme occurring in middle age, ventricular meningiomas occurring in children and young adults, and medulloblastomas occurring mostly in children. The site of occurrence of each type of glioma is also different, such as astrocytomas occurring in the cerebral hemispheres in adults and in the cerebellum in children; glioblastomas with pleomorphic forms occur almost exclusively in the cerebral hemispheres; ventricular meningiomas occur in the fourth ventricle; oligodendroglial neoplasia occurs in the cerebral hemispheres in the majority of cases, and medulloblastomas occur in the cerebellum earthworms in almost all cases. [edit]Diagnosis The diagnosis is made on the basis of age, sex, site of occurrence, and clinical course, and the type of pathology is estimated. In addition to the history and neurological examination, some auxiliary tests are needed to help diagnose localization and characterization. (1) Cerebrospinal fluid (CSF) examination: the pressure of lumbar puncture is mostly increased, and some tumors, such as those located on the surface of the brain or in the ventricles, may have increased CSF protein and leukocyte counts, and some tumor cells may be detected. However, if the intracranial pressure is significantly increased, lumbar puncture may promote the risk of cerebral herniation. Therefore, it is usually done only when necessary, such as the need to identify with inflammation or hemorrhage. In the case of significant pressure increase, the operation should be done carefully, and do not release more cerebrospinal fluid. Postoperative mannitol drip, pay attention to observation. (2) Ultrasonography: It can help to characterize and observe the presence or absence of hydrocephalus. For infants, B-mode ultrasound scanning can be performed through the fontanel, which can show tumor images and other pathological changes. (3) Electroencephalogram examination: The electroencephalogram changes of glioma are on the one hand the changes of brain waves confined to the tumor site. On the other hand, there are general widely distributed frequency and wave amplitude changes. These are influenced by tumor size, infiltrative nature, degree of cerebral edema, and increased intracranial pressure, etc. Superficial tumors are prone to confined abnormalities, while deeper tumors are less likely to have confined changes. In the more benign astrocytomas, oligodendrogliomas, etc., the main manifestation is confined δ waves, and in some cases epileptic waveforms such as spikes or sharp waves are seen. Large glioblastoma multiforme may show extensive δ waves, which sometimes can only be localized. (4) Radioisotope scanning (Y-ray encephalography): fast-growing blood-rich tumors have high permeability of blood-brain barrier and high isotope uptake. For example, glioblastoma multiforme shows isotope-concentrated image, and in the middle, there may be low-density area formed by necrosis and cysts, which should be distinguished from metastatic tumor according to its shape and multiplicity. Astrocytomas and other benign gliomas have lower concentration, which is often slightly higher than that of the surrounding brain tissues, and the image is not clear, and some of them can be negative. (5) Radiologic examination: including cranial plain film, ventriculography, electron computed tomography, etc.. Cranial plain film can show signs of increased intracranial pressure, tumor calcification and pineal calcification displacement. Ventriculography can show cerebrovascular displacement and tumor vascularization. These abnormal changes, which are different in different parts and types of tumors, can help locate and sometimes even characterize the tumor. Especially, CT scan has the greatest diagnostic value. Intravenous contrast enhancement scanning has almost 100% localization accuracy, and the correct rate of qualitative diagnosis can reach more than 90%. It can show the location, scope, shape, brain tissue reaction and ventricular compression and displacement of the tumor. However, it still needs to be combined with clinical consideration in order to make a clear diagnosis. (6) Nuclear magnetic resonance: the diagnosis of brain tumor is more accurate than CT, the image is more clear, and it can find the tiny tumor which cannot be shown by CT. Positron emission tomography can obtain images similar to CT, and can observe the growth and metabolism of the tumor and identify benign and malignant tumors. [edit]Glioblastoma The incidence of glioblastoma is the highest among brain tumors, accounting for about 40, 49%, and the combined age of onset peaks at 30-40 years old, or 10-20 years old. Gliomas occurring in the cerebral hemisphere accounted for about 51,4% of all gliomas, with astrocytomas being the most common, followed by glioblastomas and oligodendrogliomas, and the ventricular system is also a more frequent site of gliomas, accounting for 23,9% of the total number of gliomas, mainly tubulointerstitial tumors, medulloblastomas and astrocytomas, and cerebellar gliomas accounted for 13% of the total number of gliomas, mainly astrocytomas. Classification of glioblastoma: 1990, WHO will glioma classification, see the following table: astrocytic tumors mixed glioma 1, astrocytoma 1, mixed oligodendrocytoma – astrocytoma 2, mesenchymal (malignant) astrocytoma 2, mesenchymal (malignant) oligodendrocytoma – astrocytoma 3, glioblastoma choroid plexus Tumor 4, Hairy cell type astrocytoma 1, Choroid plexus papilloma 5, Subventricular giant cell astrocytoma 2, Choroid plexus carcinoma Tumor of oligodendroglial cells Neuroepithelial tumor of unspecified origin 1, Oligodendroglial cell tumor 1, Astroblastoma 2, Interstitial (malignant) Oligodendroglial cell tumor 2, Astrocytoblastoma ventriculomembranous tumors 3, Cerebral gliomatosis 1, Ventriculomas Pineal gland tumors 2, Mesenchymal (malignant) ventricular meningioma 1, Pineal cell tumor 3, Mucopapillary ventricular meningioma 2, Pinealoblastoma 4, Subventricular meningioma 3, Mixed pinealoblastoma-pineal tumor Embryonal tumors Neuronal glioblastoma 1, Medullary epithelial tumor 1, Ganglion cell tumor 2, Neuroblastoma 2, Ganglion glioma 3, Ventricular membranous cytoma 3, Mesenchymal (malignant) ganglionic glioma 4, retinoblastoma 4, central neuroblastoma 5, medulloblastoma 5, olfactory neuroblastoma Clinical manifestations of several common gliomas: astrocytoma: general symptoms of increased intracranial pressure, headache, vomiting, optic nerve papillae edema, changes in visual field, epilepsy, diplopia, cranial enlargement (in children), and vital signs. Local symptoms vary according to the location of tumor growth. ①Astrocytoma of cerebral hemisphere: about 1/3 of the patients have epilepsy as the first symptom, and about 60% of the patients have epilepsy. Cerebellar astrocytoma: ataxia of the affected limbs, clumsy movements, unsteady holding, low muscle tone and tendon reflexes, etc. ③ Thalamic astrocytoma: the first symptom of epilepsy in about 1/3 of patients. Thalamic astrocytoma: paraparesis of the contralateral limb, sensory disorder and hemiplegia, ataxia and chorea of the affected limb, mental disorder, endocrine disorder, ipsilateral hemianopsia of the healthy side, epiphora and hearing impairment. Astrocytoma of the optic nerve: mainly manifested as visual impairment and abnormal eye position. ⑤ Astrocytoma of the third ventricle: patients with obstructive hydrocephalus often present with severe episodic headache, and may have sudden loss of consciousness, mental disorder, memory loss, etc. (6) Brainstem astrocytoma: central tumors often manifest eye movement disorders, pontine tumors mostly manifest limited eye abduction, facial nerve and trigeminal nerve involvement, medulla oblongata tumors often manifest swallowing disorders and changes in vital signs. Glioblastoma: the tumor is highly malignant with rapid growth and short disease duration, most of them are within 3 months from the appearance of symptoms to the consultation, high intracranial pressure symptoms are obvious, 33% of the patients have epileptic seizures, 20% of the patients have mental symptoms such as apathy, dementia, mental retardation, etc., and the patients may have hemiparesis of varying degrees, hemiparetic sensory disorder, aphasia and hemianopsia. Oligodendroglioma and mesenchymal (malignant) oligodendroglioma: epilepsy is often the first symptom, psychiatric symptoms such as emotional abnormality and dementia are predominant, hemiparesis, hemiplegia, hemiplegia, and aphasia may occur by infringing on motor and sensory areas, and symptoms of high cranial pressure appear later. Medulloblastoma: ① fast tumor growth, obvious high cranial pressure symptoms ② cerebellar function damage manifested as hobbling gait, unsteady walking. ③ Diplopia, facial paralysis, enlarged head (in children), choking, etc. ④ Tumor metastasis is an important feature of medulloblastoma. Ventricular meningioma ① Symptoms of increased intracranial pressure ② Symptoms of brainstem compression (vomiting, choking, difficulty in each pharynx, hoarseness, dyspnea), cerebellar symptoms (unsteady walking, nystagmus, etc.), and hemiparesis, suprachiasmatic movement disorders. The recurrence rate after surgery is almost 100%, and intravertebral metastasis is easy to occur. Choroid plexus papilloma: 1. Hydrocephalus and tumor occupancy cause high cranial pressure symptoms, and children commonly have enlarged skull; mental apathy, lethargy or irritability. 2.Tumor located in the lateral ventricle has contralateral pyramidal fasciculus sign; those in the posterior cranial recess have unsteady walking, nystagmus, ataxia, and those in the third ventricle have difficulty in binocular upgaze. Pineal cell tumor: increased intracranial pressure; hearing and eye movement disorders, affecting the lower part of the visual acuity manifested as urolithiasis, lethargy and obesity, etc., and endocrine symptoms manifested as stagnant development of the sexual characteristics or non-development; epileptic seizures and impaired consciousness can be seen in some patients. [edit this paragraph] Treatment The growth of glioblastoma is characterized by infiltrative growth, and there is no obvious boundary with normal brain tissue, most of them are not limited to a lobe, and they are finger-like to the outside of the brain tissue to destroy the brain tissue in depth, and the growth of those who are benign is slow, and the course of the disease is long, and it takes two years on average from the emergence of the symptom to the time of medical consultation, while the growth of those who are malignant is fast, and the course of the disease is short, and it is within three months from the emergence of the symptom to the time of medical consultation in the majority of them, and 70-80% of them are within half a year. Most of the tumors grow rapidly and have a short course. At present, the treatments for glioma at home and abroad are generally surgery, radiotherapy, chemotherapy, X-knife, γ-knife and so on. Surgery: Based on the growth characteristics of glioma, theoretically, it is impossible to completely remove the tumor by surgery, and some tumors growing in the brain stem and other important parts of the brain cannot be operated at all. Therefore, the therapeutic purpose of surgery can only be limited to the following five aspects: (1) to clarify the pathological diagnosis, (2) to reduce the volume of the tumor and lower the number of the tumor cells, (3) to improve the symptoms and relieve the symptoms of high cranial pressure, (4) to prolong the life and create the time for the following other comprehensive treatments, (5) to obtain the tumor cytokinetics, and (7) to obtain the tumor cytodynamics. (iv) prolong life and create time for other comprehensive treatment; (v) obtain tumor cytokinetic data to provide the basis for finding effective treatment. Radiotherapy: Radiotherapy is the routine treatment for almost all types of gliomas, but the evaluation of the efficacy is different, except for medulloblastoma, which is highly sensitive to radiotherapy, and ventricular meningioma, which is moderately sensitive, the other types of gliomas are insensitive to radiotherapy, and it has been observed that the prognosis of those who have radiotherapy and those who do not have radiotherapy are the same. In addition, the effect of radiation-induced radionecrosis on brain function should not be underestimated. X-knife and gamma-knife belong to the category of radiation therapy. Due to the location of the tumor, the size of the tumor (generally limited to less than 3 cm) and the sensitivity of the tumor to radiation, the scope of treatment is limited, and it is currently believed that gliomas, especially malignant astrocytomas of grade Ⅲ-Ⅳ or glioblastomas are unsuitable for treatment with R-knife. However, as gamma knife doctors continue to explore the treatment of gliomas, gamma knife dose fractionation treatment of large gliomas with tumor diameters exceeding 3 cm has achieved excellent clinical results. Chemotherapy: In principle, it is used for malignant tumors, but chemotherapeutic drugs are limited to the blood-brain barrier and the toxic side effects of the drugs, the efficacy is not yet certain, and the commonly used BCNU, CCNU, VM-26 and so on, the effective rate is below 30%. [Editor’s note: The incidence of the population and types of 1, oligodendroglioma and mesenchymal oligodendroglioma: brain tumors mostly grow in the white matter, soft, infiltration is relatively extensive, can be protruded into the ventricles and cortical surface, some tumors can be cystic changes. Some tumors may produce mucoid changes. Aggregation into jelly-like material, cell nuclei rounded. Malignant oligodendrogranulocytoma has a more rounded shape. There is more cytoplasm, and individually, tumor cells are seen to spread with the cerebrospinal fluid. Clinical oligodendrocytic glioma mostly grows slowly, with a long course of disease, and the average period from symptom to consultation is 2-3 years. Epilepsy is the first symptom of this disease, and extensive infiltration of the tumor can be seen as emotional abnormality and dementia, and the increased intracranial pressure can be seen later when the tumor infringes on the motor and sensory areas, which will correspondingly produce hemiplegia, hemiparetic sensory party disorder and motor sensory aphasia, and so on. 2.Optic nerve cell glioma: the tumor develops in the optic nerve foramen and optic cross section, and the tumor is mainly located in the posterior half of the eyeball, the optic nerve foramen can be expanded due to the growth of the tumor, and the tumor at the optic cross section can involve the optic cross section, spread to the basal part of the thalamus and hypothalamus, and even protrudes into the tricortical ventricle or compresses the tricortical ventricle to make the lateral ventricles of the two sides hydrops, and the tumor can also involve the whole optic nerve, and make the optic nerve present a diffuse type of coarseness and thickening. 3.Optic cross section Cellular glioma: the tumor commonly occurs in adolescents or young adults, with low incidence and high malignancy. Gliomas may originate from the glial cells of the optic nerve and optic intersection, and gliomas originating from the optic nerve mostly occur in children, while gliomas originating from the optic intersection may infiltrate the hypothalamus, and gliomas originating from the hypothalamus may also spread to the optic intersection. Gliomas of the optic nerve are mostly hairy cell astrocytomas, which are relatively benign tumors. Gliomas of the optic chiasm are more malignant, and the tumors are often slightly cystic, with or without accumulation of proteinaceous material, producing a mucinous tumor-like phenomenon. [edit]Health care 1, Dietary fiber and glioma study results showed that the control group consumed more vegetables and fruits than the case group and showed a negative association. Suggesting that vegetables and fruits have a protective effect on gliomas, Martin et al. found that vitamin-rich fruits and vegetables are protective against brain tumors, especially citrus fruits are more protective against brain tumors. Vegetables, fruits and cereals are rich in dietary fiber, mainly cellulose, lignin, hemicellulose, polypentose, gum and pectin, etc. These substances can reduce the incidence of colon cancer and other tumors. Dietary fiber can prevent cancerous lesions induced by certain chemical carcinogens, and in turn can modulate hormones or endogenous tumor suppressors in the body. Regarding the anti-cancer mechanism of dietary fiber, it is currently believed that: ① dietary fiber can reduce the concentration of carcinogens in the colon; ② it can shorten the passage time of poisons in the intestinal lumen and reduce the contact time between carcinogens and tissues; ③ it can affect the production of certain carcinogens or pre-carcinogens; and ④ it has a regulatory effect on the endocrine system, thus affecting the generation and development of tumors. 2, vitamins and glioma vegetables, fruits and plants are rich in fiber, but also rich in vitamins. In addition to dietary fiber, vitamins play a key role in the preventive effect of vegetables and fruits on tumors. Carrots are rich in carotenoids, while tomatoes, oranges, apples and other vegetables are rich in vitamin C, which are negatively associated with the development of gliomas.Byers found that carotenoids significantly reduce the incidence of lung cancer, and plant vitamin A is more effective in preventing cancer. Vitamin A differentiates epithelial cells into specific tissues, causes squamous cell carcinoma and other cellular cancers to subside in the body, and activates the anti-tumor immune system. Fresh fruits and vegetables rich in vitamin C have obvious preventive effects on tumors. The mechanism of action of vitamin C is to inhibit the synthesis of endogenous nitrosamines and inhibit the transformation of tissue cells to carcinogenic compounds, and even reverse the transformation of already transformed cells. It is because of the anti-cancer effect of vitamin C, it is generally recommended that the daily intake should be more than 100mg. Vitamin E can inhibit the formation of carcinogenic nitrosamines and free radicals, protect the normal differentiation of cells and enhance the immune function. 3, N-nitroso compounds and glioma risk factors in food are mainly N-nitroso compounds and their precursor substances, namely, dimethylnitrosamine and amyl nitrite. Salted, cured and smoked fish contain large amounts of nitrosamines that can form nitrites, and Burch et al. found that cured and smoked meat foods presented a meaningful association with brain tumors. The current study also found an association between sauces and sauerkraut and brain gliomas, and salted fish also showed a meaningful association in a univariate analysis. Humans can be exposed to N-nitroso compounds through multiple pathways such as smoking and ingestion of food, as well as endogenous N-nitroso compounds, and ingestion of substances such as amyl nitrate and amyl nitrite can be converted to N-nitroso compounds in the body.HeinerBoeing et al. found an association between ingestion of processed and preserved fish, cheeses, and other meat products and brain tumors, with cooked ham, processed pork chops, fried bacon were the most significant. Meat products often contain N-nitrosodimethylamine (NDMA), N-nitrosopyrrolidine (MPYR), and N-nitrosohexachloropyridine (NPIP), but these substances may not play a major role. Because it does not induce tumors in animals, only N-nitrosourea induced brain tumors in animals in animal experiments, but other forms of these substances have been shown to be mutagenic, as have polycyclic aromatic hydrocarbons and heterocyclic amines. More evidence from epidemiologic and laboratory studies is needed to determine the relationship between dietary factors and the development of gliomas. Because of the complexity of the causes of glioma formation, other possible factors and their influence on dietary factors should be considered when studying dietary factors.