Brain cancer - Symptoms, Types, Causes, Complications, Treatment

Brain cancer definition

Brain cancer, also referred to as intracranial neoplasms, is a group of malignant(cancerous) tumors that develop in the brain or surrounding tissues. Cancer is a group of diseases identified by uncontrolled growth and spread of abnormal cells in the body. These cells can become tumors and interrupt the functioning of organs and tissue. Brain cancer can develop from brain tissue itself known as a primary brain tumor or because of cancer spreading from another part of the body known as a metastatic brain tumor. 

A team of medical specialists, including neurologists, neurosurgeons, oncologists, and other healthcare professionals interact to develop the most effective therapy and support care for brain cancer.

Brain cancer meaning

Brain cancer is the combination of two words in which

• The word “brain” is a derivation from Old English “braegen," which originated from the Proto-Germanic source “bragnan” (source also of Middle Low German bregen, Old Frisian and Dutch brein). All the derivations describe it as a “soft, greyish mass which fills the cranium of any vertebrate." 
• The term "cancer" is taken from the Greek word “karkinos”, which means "crab" and "tumor". Hippocrates, a Greek physician (460-370 BC), is credited with using the word approximately 400 BC to describe tumors. 
  

Brain cancer statistics

Brain cancer statistics worldwide

Brain cancer is a major health concern worldwide, but its prevalence and incidence vary by place and population (as of September 2021). Brain cancer accounts for nearly two percent of all cancer cases worldwide. In 2019, 347,992 newly identified cases of brain cancer were reported globally, with 187,491 (54%) males and 160,501 (46%) females being diagnosed.

Brain cancer statistics in India

In India, the incidence of central nervous system (CNS) tumors ranges between 5 and 10 per 100,000 people, with an increasing trend, and constitutes 2% of all malignancies (cancers). Male incidence rates for brain cancer range from 2.53 (Chennai registry) to 4.14 (Delhi registry), while female incidence rates vary from 1.46 (Bhopal registry) to 2.66 (Delhi registry). Brain cancer incidence rates have increased in both sexes across all registries except in Delhi. The incidence increased for the Bhopal registry and decreased for the Delhi registry, but was not statistically significant. In Mumbai, Chennai, and Bangalore registries, there was a substantial increase of over 3% in age-adjusted incidence rates of brain cancers in both sexes.

Brain cancer types

Brain cancer, often known as a brain tumor, is the abnormal growth of cells in the brain. These tumors can be either benign (noncancerous) or malignant (cancerous). Brain Cancers (Typically malignant) include the following types: 

• Chordoma
• Chondrosarcoma
• Medulloblastoma
• Olfactory neuroblastoma
• Lymphoma
• Gliosarcoma
• Rhabdomyosarcoma
• Paranasal Sinus Cancer
• Atypical teratoid/rhabdoid tumor (AT/RT)

Chordomas: A rare type of bone cancer (<1%) seen in the skull base or the lower back. It can pressure the nearby nerve tissue with its invasion. Despite displaying benign tendencies with its slow growth, its refractory nature is as lethal as a malignant as it keeps returning to spread to other areas.

Chondrosarcoma: A malignant bone cancer that develops between 50-70 years of age, affecting the cartilage. This aggressive cancer could grow in the thighbone, arm, pelvis, etc, spreading to the head and spine. It could also develop directly in the face bones or skull base.

Medulloblastoma: One of the most frequent malignant brain tumors in pediatric patients (5-9 years), medulloblastoma arises in the cerebellum. It is of various types with varying aggressivity.

Olfactory neuroblastoma: A rare malignancy associated with nose bleeds and difficulty breathing from the nose, olfactory neuroblastoma develops in the nose in the olfactory nerve (nerve transmitting olfactory impulses (smell) to the brain). Gradually, patients lose their sense of smell.

Lymphoma: A type of tumor that forms in the lymphatic system (part of the body's immune system). Lymphomas can either spread from other body parts to the brain or directly form in the brain (primary central nervous system lymphomas). Usually, primary CNS lymphomas are treated with chemotherapy and radiation.

Gliosarcoma: Rare type of glioma combined with other supportive tissues. These can be aggressive and spread to other areas apart from being resistant to therapy.

Rhabdomyosarcoma: A rare soft tissue cancer occurring not only in the head but also in many parts of the body (in muscles). Children have more of an affinity to develop rhabdomyosarcomas, which starts with complaints of the eyes or face.

Paranasal Sinus Cancer: Formed in the cells lining the hollow spaces of the bones around the nose (maxillary sinuses (in the cheekbones under the eyes) and the ethmoid sinuses (beside the upper nose)).

Atypical teratoid/rhabdoid tumor (AT/RT): An embryonal tumor that typically affects children lesser than seven years of age. It is an aggressive cancer with low survival rates despite providing therapy. 

Brain cancer symptoms

The symptoms of brain cancer may change depending on the location and the size of the tumor within the brain. Below are some of the main symptoms of brain cancer:

• Cognitive changes: These include memory issues, trouble concentrating, confusion, changes in personality, and changes in judgment.
• Headaches: They can be persistent and severe, potentially worsening over time. Headaches may be more severe in the morning or after waking up.
• Vision problems: These may include blurry vision, double vision, and loss of peripheral vision.
• Seizures: An uncontrolled electrical activity in the brain can cause seizures. Seizures vary in severity from mild to severe and may cause loss of consciousness or convulsions. 
• Nausea and vomiting: It occurs mainly when accompanied by additional symptoms such as headaches or vision abnormalities.
• Balance and coordination difficulties: These include trouble walking, losing balance, or controlling movements.
• Speech difficulties: These include difficulty finding words, slurred speech, and difficulty understanding speech.
• Behavioural changes: These may include mood swings, irritability, depression, or other unexplained behavioral changes.
• Sensory alterations: These include tingling, numbness, or decreased sensation in the legs and arms.
• Weakness or paralysis: It refers to gradual or sudden weakening in the legs or arms, typically on one side of the body.
  

Brain cancer causes and risk factors

While the specific reasons for brain cancer are unknown, research indicates that some risk factors may raise the likelihood of developing brain cancer, which are as follows:

Non-modifiable factors

• Age
• Gender
• Immune system 
• Hormonal factors
• Family history

Modifiable factors 

• Exposure to rays
• Nutrition
• Smoking
• Alcohol
• Mobile phones
• Aspartame
  

Non-modifiable factors

 Some risk factors of brain cancer cannot be altered (changed), known as non-modifiable risk factors. It includes:

• Age: While brain cancer can develop at any age, it is most commonly identified in young children and the elderly.
• Gender: In general, men have a greater risk of developing brain cancer than women.
• Immune system: The exact level of immunological decrease that leads to cancer cell development in patients remains uncertain. Cancer cells release immunosuppressive cytokines, reducing immunity and promoting tumor growth in the body. Immunocompromised people, either due to a congenital or acquired cause, such as acquired immune deficiency syndrome (AIDS) or human immunodeficiency virus (HIV), are more likely to develop certain types of brain cancer.
• Hormonal factors: According to Cowppli-Bony et al., the incidence of brain tumors rises during menarche and menopause and falls after hormone therapy.
• Family history: A family history of cancer may indicate a genetic predisposition due to similar environmental factors among family members.

Modifiable factors

Some risk factors of brain cancer can be changed, known as modifiable risk factors. It includes: 

• Exposure to rays: Exposure to high and moderate levels of ionizing radiation increases the risk of developing nervous system tumors.
• Nutrition: Consuming fruits and vegetables has an inverse association with brain tumors. Vitamins C, E, and phenylol found in fruits and vegetables, as well as carotenoids and folate, play a role in the development of brain tumors. On the other hand, antioxidants and certain phytoestrogens slow tumor growth. Processed meat and other food groups have been linked to higher infection rates.
• Smoking: It is one of the leading causes of cancer in humans. Smoking increases the adsorption of polycyclic aromatic hydrocarbons and nitrous chemicals.
• Alcohol: Alcohol intake is associated with 3.6% of global cancers. Alcohol intake has been associated with lower cancer survival rates and tumor growth.
• Mobile phones: Increased use of mobile phones raises the incidence of brain tumors in individuals over 20 years old.
• Aspartame: More than 20 crore individuals worldwide eat aspartame, an artificial sweetener. A daily intake of 20 mg of aspartame raises the risk of nervous system tumors. Long-term consumption can lead to myelin degeneration and an increased chance of developing a tumor.

Frequently Asked Questions (FAQs) on Brain cancer

What is brain cancer?

Brain cancer is the uncontrolled proliferation(growth) of cells in the brain. Brain cancer includes a wide range of tumors that affect various types of brain cells. Brain cancers can grow quickly or slowly over many years, depending on the location and type of cell involved. Brain cancers are generally hard to treat, and a complete cure is sometimes impossible.

How does brain cancer kill you?

Malignant brain tumors are cancer in nature. They often grow quickly and invade neighboring healthy brain areas. Brain cancer can be fatal (causing death) because of the changes it causes to the brain's vital structures.

Can prostate cancer spread to the brain?

Prostate cancer usually spreads to the pelvic lymph nodes, axial skeleton, and lungs. Brain metastases from prostate cancer is rare and usually found after death. It is quite rare for metastatic prostate cancer to occur primarily in the brain.

What tests are done to diagnose brain cancer?

Brain cancer can be diagnosed using computed tomography (CT) scan, magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), positron emission tomography (PET) scan, single photon emission computerized tomography (SPECT), biopsy and lumbar puncture.

What is stage four brain cancer?

Glioblastoma multiforme (GBM) is a stage four brain cancer that arises from the glial cells (brain cells). It is the most severe type and aggressive tumor. The tumor develops new blood vessels as it grows because of the abnormal tumor cells. The tumor may develop necrosis (death of cells).

Can stem cells cure brain cancer?

California Institute for Regenerative Medicine (CIRM)- funded researchers are trying ways to genetically engineer stem cells to produce cancer-killing molecules. When transplanted into the brain, the stem cells look for cancer cells and deliver the treatment directly.

Why do brain cancer patients sleep so much?

Brain cancer patients sleep so much because the tumor is close to the orexin-producing cells present in the hypothalamus, which are essential in maintaining wakefulness. The tumor may destroy or affect these cells during partial or whole-brain radiation or surgery.

Has anyone survived brain metastases?

Ten and a half years ago, people suffering from brain metastases survived for nearly less than six months. Nowadays, treatment options for brain metastases have improved, and individuals suffering from brain metastases live longer than before. 

Is brain cancer painful? 

Headaches associated with brain cancer are persistent and severe, potentially worsening over time. Headaches may be more severe in the morning or after waking up. They are usually referred to as dull, pressure-type headaches. These patients may also suffer from stabbing (sharp) pain. 

Department of Oncology | Neurology