REMEMBERING PROF. D.K. CHABRA BY HIS LECTURE ON BRAIN CANCER

 

 

Dr. D.K. Chabra was a Reader in the Department of Neurosurgery when we were doing our M.S. and was always present in the Neurosurgery department either attending to his patients, or operating, or addressing some administrative problems or attending to the maintenance of some surgical equipment. You could never find him sitting idle, work was his way of relaxation. I have, in the past, written about Prof. Chabra in one of my blogs, and if you have missed it, please click: https://surajitbrainwaves.blogspot.com/2020/06/remembering-prof-d-k-chabra-today.html

He married very late in life and in his bachelor days was truly married to neurosurgery, and so had no time for family. We, residents and students were his family and to us he was a huge inspiration. I did my first carotid angiography, my first cranial burr hole, my first craniotomy and my first drainage of subdural haematoma with him breathing down my neck! He was a strict stickler of S.O.Ps and these got ingrained in our DNA. Training with him was always hands-on. 

When Sanjay Gandhi Post Graduate Institute of Medical Sciences was established, he was hand-picked by the Director to build the Department of Neurosurgery from scratch. It was a huge loss to our Institution, but the Neurosurgery department in S.G.P.G.I. flourished under his care. His influence in the new Institute was far beyond his own speciality, and his contribution in the building of his new Institute and its work culture was profound.

When we were doing our M.S in General Surgery, we the residents of Surgery, who were about to appear in the M.S. examination, would request particular teachers to teach us particular subjects, of which they were true domain expert. Thus we would request Prof. A.K. Wakhlu to revise Ano-rectal malformations with us, Dr. G.K. Singh to teach us Bone Tumours, and Prof. S.K. Bhatnagar to teach us Cleft Lip & Palate and Hypospadias. These classes would occur in the evening and no teacher ever said no to our request. One day we approached Dr. D.K. Chabra and requested him to teach us Brain Cancers. In his customary style Dr. Chabra said “give me 3 days to collect some teaching material and we will do this at 7PM next Friday. So, this is what I could recover from my notes of that evening’s class. 

Brain cancer refers to a growth of abnormal cells in the brain. These tumors can start in the brain (primary brain tumors) or spread to the brain from cancers elsewhere in the body (metastatic tumors).

Some brain tumours are non-cancerous (benign) while others are malignant “brain cancers” that grow quickly and invade tissue. Even benign tumors can cause serious symptoms by pressing on brain structures.

 

Types of Brain Cancer

Brain tumours are classified by the cells they originate from.

Glioblastoma (GBM):

This is an aggressive cancer arising from glial (supportive brain) cells, and the most common malignant brain tumor in adults. GBM accounts for about 16% of adult primary brain tumors. It grows rapidly and is difficult to cure; five-year survival rates are very low (around 6–9% for patients in their mid-40s to mid-50s). GBM often affects adults over 45 and can cause headaches, personality changes, or seizures as it progresses.

 

Meningioma:

This is a tumor of the meninges, the membranes covering the brain and spinal cord. Meningiomas are usually benign (non-cancerous) and slow-growing. They are the single most common brain tumor type, making up roughly 46% of adult brain tumors. Meningiomas often occur in people over 60 and more frequently in women, and can grow for years before causing symptoms like headaches or focal neurological deficits. Because they are often treatable (usually with surgery and/or radiation), survival rates are high – about 79% five-year survival for patients in their late 40s and 50s.

 

Astrocytoma:

This is a tumor originating from astrocytes, the star-shaped glial cells. This category includes a range of gliomas from lower-grade (grade II) astrocytomas to grade III (anaplastic) astrocytomas. These tumors tend to grow slower than GBM (which is actually considered a grade IV astrocytoma) and often affect middle-aged adults. While they are malignant, they generally have better outcomes than GBM; for example, a diffuse low-grade astrocytoma has around a 46% five-year survival in people age 45–54. Astrocytomas can cause seizures, cognitive changes, or weakness, and sometimes progress into more aggressive forms over time.

 

Metastatic Brain Tumors:

These are cancer that has spread to the brain from another organ (such as the lung, breast, colon, or skin). Metastatic tumors (also called secondary brain tumors) are actually more several times more common than primary brain cancers. Virtually any cancer can spread to the brain, but lung cancer, breast cancer, melanoma, and kidney cancer are among the most likely to do so. These tumors often present with symptoms similar to primary brain tumors. Treatment typically focuses on controlling the spread by radiation or surgery and managing symptoms.

 

Early Symptoms and Warning Signs

Brain tumors can produce a wide range of symptoms. In adults over 45, it’s especially important to recognize new or unusual symptoms and not simply attribute them to “normal aging.” Early detection of a brain tumor can greatly improve outcomes. Common early signs include:

1.      Frequent headaches: Especially headaches that are new, persistent, and worse in the morning or wake one from sleep. These may be accompanied by nausea or vomiting. While many adults get headaches, a pattern of headaches that steadily worsens over time or is coupled with other neurological symptoms should be evaluated carefully.

2.      Seizures: A seizure in someone with no prior history of epilepsy is a red flag for a brain tumour until proven otherwise. About one-third of brain tumour patients experience seizures as an initial symptom. Any sudden convulsion, unusual spell of confusion, or loss of consciousness warrants prompt medical attention.

3.      Cognitive or personality changes: Brain tumours can subtly affect memory, thinking, and mood. Family members might notice the person becoming more confused, forgetful, or having trouble following conversations and simple commands. Some tumors cause personality changes – for example, a formerly calm person may become easily irritable or apathetic. Such changes, especially if they worsen over weeks or months, should be investigated.

4.      Weakness or balance problems: Unexplained weakness or numbness in an arm or leg, or clumsiness and balance difficulty (stumbling, swaying while walking), can indicate a tumor affecting the motor areas or cerebellum. Sometimes this is mistaken for stroke; unlike a stroke, which develops suddenly, tumor symptoms often develop gradually. If you notice progressive loss of coordination or one-sided weakness, investigate for brain tumour.

5.      Vision or speech disturbances: Tumours in certain brain regions can cause blurred or double vision, loss of peripheral vision, or other visual changes. Likewise, a growth affecting language centers may lead to speech problems – difficulty finding words, slurred speech, or trouble understanding others. These symptoms, particularly if they are new and getting worse, should be promptly evaluated. What is to be appreciated is that the symptoms depend on the tumor’s location and growth rate. A slow-growing meningioma might cause very subtle issues for years, whereas an aggressive glioblastoma can produce symptoms that escalate over a short time. In any case, new neurological symptoms in midlife or later age should not be ignored.

 

 

How Brain Cancer is diagnosed?

If a brain tumour is suspected, you will have to perform a series of evaluations and tests to confirm the diagnosis and identify the tumor type. The typical steps include:

Neurological exam: The first step is usually a thorough exam of the nervous system. Check for  reflexes, muscle strength, vision, hearing, balance, coordination, and cognitive function. Specific deficits (for example, weakness in the left arm or trouble with peripheral vision) can provide clues about where in the brain a tumor might be located.

 

Imaging tests: If exam findings suggest a possible brain issue, imaging is done to look inside the skull. A Carotid Angiogram is a quick X-ray based scan that may be done initially, especially in emergency situations or to diagnose a space occupying lesion and rule out other problems. However, the preferred imaging for brain tumors is CT Scan. Even these have limitations as it is difficult to distinguish tumor tissue from normal brain or scar tissue and assess how active or aggressive the tumor might be.

 

Biopsy: Imaging alone can strongly suggest a tumor, but the definitive diagnosis comes from examining tumor cells under a microscope. To obtain cells, a biopsy is performed. In many cases, if the tumor is accessible and operable, a neurosurgeon will remove as much of it as safe during surgery and send samples to the lab. If the tumor is in a tricky location not easily removable, a smaller stereotactic needle biopsy can be done. A pathologist then analyzes the tissue to determine the tumor type and its grade.

 

Additional tests: These may include blood investigations and a spinal fluid exam in certain cases, but the neurological exam, imaging, and biopsy are the cornerstone of diagnosis.

 

Age distribution:

The risk of brain tumors increases with age. The median age at diagnosis is around 60 years. Brain and other central nervous system cancers are most frequently diagnosed in people between 65 and 74. Over two-thirds of brain tumor cases occur in those above 40. In older adults, brain tumors rank among the more common cancers – they are the seventh most common type of tumor and the sixth leading cause of cancer-related death in people over 40.

 

Survival rates:

Thanks to advances in treatment, many patients live with brain tumors for years. Overall, considering all primary brain tumors (including benign), the five-year survival rate for adults is around 72%. For malignant brain tumors in older adults, survival is much lower. Among adults aged 40 and over, only about 21% survive five years. Glioblastoma has especially poor outcomes – around 9% for ages 45–54, and around 6% for ages 55–64. For benign tumors, survival is much better: about 90% in those over 40. For example, meningioma patients typically see five-year survival rates of 80% or higher. Grade II/III astrocytomas fall in between, with survival rates from 29% to 46% in middle-aged adults, depending on grade.

It’s important to remember that survival statistics are averages. Individual outcomes vary based on tumor type, location, genetics, treatment options, and overall health.

 

Risk Factors for Brain Cancer in Older Adults

Most brain cancers do not have a clear cause, but certain factors can increase the risk:

1.      Advancing age is one of the strongest risk factors. Risk increases significantly after age 45 and peaks in the elderly.

2.      Sex: Women are more likely to develop benign brain tumors, while men are more likely to develop malignant ones like glioblastoma.

3.      Radiation exposure: High-dose ionizing radiation to the head increases the risk, especially when received for previous cancer treatments.

4.      Genetic conditions: Rare syndromes like NF1, NF2, Li-Fraumeni syndrome, and tuberous sclerosis can increase risk, though they are uncommon.

5.      Metastasis from other cancers: Lung, breast, kidney, and skin cancers are most likely to spread to the brain.

 

Thus ended Dr. Chabra’s class on Brain Cancers. He had brought a bunch of Carotid Angiograms of patients with Brain Cancers and he demonstrated Meningiomas, Secondary deposits and other intra-cranial space occupying lesions. He also projected some histopathology slides of different brain tumours to revise the types of tumours. Our institution did not have a CT Scan and MRI then and Carotid Angiogram was our only radiological investigation for diagnosing these tumours. Dr. Chabra then left with his two residents to complete his ward rounds.

Remember, this was Brain Cancer before the advent of MRI and fancy genomic profiling, targetted treatment, IDO1 inhibitors, Focoused Ultrasound, Motor Protein inhibitors, Immunotherapy, and Gamma knife.