Why Cancer is so Deadly?

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Why Cancer is so Deadly?




Cancer is one of the most globally concerning medical conditions that exist today, being the second most leading cause of death around the globe.


The most common type of cancer being breast cancer affects 2.26 million people across the globe which lung cancer affects 2.21 million people based on a report in 2020.


It is characterized by the development of abnormal cells which have the capacity to divide without a particular order or control and can destroy other normal body cells and tissues. Certain cancers can spread throughout your body and cause tumours at more than one place in the body.


Our body has trillions of cells each of which has a capacity to grow and divide to replace the old worn-out cells and take their place. Each cell has its own specific life cycle and the time between which they finished one cycle of division and produce a new cell from existing ones. This depends on each type of cell.


Different cells have different times of completion of the division to produce new cells from existing ones. Cancer describes the entire process by causing changes in their genetic material or in the DNA in the form of mutations which leads to abnormal uncontrolled growth of cells.


Mutations are not something new in a cell. Mutations happen all the time but most of the time the cell rectifiers the mutations by itself. Mutations mostly happened inside the DNA of a cell. The DNA is mainly responsible for giving out instructions to the cell as to when to divide and what kind of functions to perform. When the mutations are not rectified by the cell themselves it leads to cancerous growth.


Mutations form new cells when they are not needed and also cause many cells to survive and live for longer when it's time for them to die and hence by both these ways, the total number of cells in the body rises to a very uncontrollable level which forms tumours. Tumours can cause a variety of health issues mainly depending on which part of the body they appear in.


There are two types of tumours:


  • Benign Tumour: This type of tumour is usually non-cancerous and remained confined to one area of the body. This means they do not travel from one place to another and cause multiple tumours within the body.


  • Malignant Tumors: Malignant tumours are cancerous and can cause problems in many parts of the body.


Tumours can sometimes migrate through the bloodstream and the lymphatic system to various other parts of the body by a process called metastasis. Metastatic cancers are more fatal and require much more advanced treatment methods than normal cancers.


Types of Cancer:


Types of Cancer

Even if cancer decides to spread to other parts of the body, they are named for the particular location in the body they are lodged and also the type of cells they are composed of.

For example, lung cancer is the name given to a tumour in any part of the lungs.


  • Carcinoma is cancer that affects the skin on the tissues which line other organs of the body.
  • Sarcoma is the cancer of the bones muscles blood vessels cartilage etc. Basically, all the connective tissues of the body.
  • Leukaemia is a cancer of the bone marrow. Bone marrow is responsible for manufacturing blood cells in the body.
  • Lymphoma and myeloma are the names given to the cancers related to the immune system.


Causes of cancer:


Causes of cancer

Cancer is generally caused by changes or as we call it mutations to the DNA which is present inside of the cells. The DNA inside the cells is grouped into a large number of individual genes and each gene contains instructions that tell the cell about the functions and have to perform and information about its growth and divisions.

Mutations can cause malfunctioning in the instructions given to the cell which can lead to the cell stopping its normal function and become cancerous.


Gene mutations can cause the following effects on a cell:


1) Allows rapid growth of cells: Gene mutation can instruct a cell to grow and undergo division much more rapidly than normal which ends up creating many new cells.


2) Fails to suppress uncontrolled growth of the cell: There is a certain amount or number each cell has to maintained inside the body. Normal cells know exactly when to stop dividing so that the right number of its type has reached inside the body and does not exceed the right amount of cells of that particular type.

But cancer cells, on the other hand, lose the tumour suppressor genes which tells the genes to stop growing when the number of cells has exceeded the normal. As a result, more and more cells accumulate leading to cancer in the particular body part.


3) Faults while correcting DNA errors: Certain genes known as DNA repair genes detect errors within a cell's DNA and correct the errors. Mutations will lead to the errors not being rectified leading to the formation of a cancerous tumour.


Causes of Mutations:


Causes of Mutations

1) Mutations that you are born with: Certain types of mutations can be inherited from your parents. A very small percentage of cancers occur from mutations of such kinds.


2) Mutations that occur post-birth: These are the mutations that you are not born with but instead develop after your birth. Activities such as smoking, exposure to radiation, viruses and cancer-causing chemicals, obesity, hormones, lack of exercise, etc can stimulate mutations.


Gene mutations that you are born with and the mutations you develop after birth interact together and leads to cancers.

For example, a mutation that you might have inherited from your parents most probably will not be the cause of your cancer. If by any means you develop cancer post-birth by all the lifestyle changes, the particular mutation that has occurred as a result of lifestyle changes coupled with the inherited mutations will finally cause cancer in your body. Cancer does not occur due to one mutation in the cells. It occurs due to multiple mutations within your cells.


Risk Factors:

Certain factors that increase your risk of getting cancers are:


Certain factors that increase your risk of getting cancers are



Probability of developing cancer increases as you age but cancer take many years, probably even decades to develop. That explains why the majority of the people who are diagnosed with cancer are over 50 to 60 years of age. 

This should not be misinterpreted as cancer occurs only in older people. Older people have more chances of getting cancer but that does not mean younger people will never get cancer. There are countless cases of young children even toddlers getting cancer so do not get misguided by the fact that more old people get cancer.


2) Lifestyle:


Smoking, drinking, excessive exposure to sun or very frequent sunburns, obesity, exposure to radiation or even having unsafe sex (transmission of Human Papilloma Virus) can contribute to cancer.


3) Hereditary:


Having a family history of cancer can mean that there are certain mutations in genes that are passed down to you before you were born. Such types of cancers are not very common.


4) Health Conditions:


Certain health conditions such as ulcerative colitis can increase your chances of developing cancer.


5) Environment:


If the place where you live is surrounded by harmful chemicals are radiation or second-hand smoke, you have a chance of developing cancer in the future just by inhaling that smoke and the chemicals even if you are not a person who smokes or drinks.

Chemicals such as asbestos and benzene have been known to increase the risks of cancer.




Pain: Can be reduced during treatment by using certain medications


  • Fatigue: Usually temporary, occurs during therapy.


  • Breathing Problems: Shortness of breath is common but can be managed.


  • Nausea


  • Diarrhoea


  • Constipation


  • Weight Problems: Weight loss is common as in cancer. Normal cells are starved from nutrients by the cancer cells. This is quite difficult to treat. Even supplementary administration of artificial nutrition through tubes into the stomach does not help manage weight loss. In fact, weight loss is one of the strong indicators of cancer in a person's body.


  • Chemical Changes: Cancer causes chemical imbalance within your body and leads to other complications. Excessive thirst, constipation, frequently urinating, etc can occur due to chemical imbalance.


  • Brain and Nervous system problems: Cancer can cause loss of function of various body parts due to pressing on certain nerves in the body. Cancers related to the brain can cause strokes and headaches.


  • Immune Reactions: Paraneoplastic Syndrome, characterized when the body’s immune system attacks healthy cells when reacting to the presence of cancer cells in the body. These can lead to seizures.




Treatment for cancer varies from person to person as many factors such as type and the stage of cancer have a vital role in determining the type of treatment.


1) Primary Treatment:


This involved completely removing cancer or killing the cancer cells present in your body.

The most common mode of primary cancer treatment is surgery. Radiation therapy or chemotherapy may be used if your cancer is particularly sensitive to these methods as a mode of primary treatment.


2)Adjuvant Treatment:


Adjuvant treatment can be employed when it is required to kill the remaining cancer cells that remain inside your body after the primary treatment to reduce the possibilities of new cancer developing.

Chemotherapy, hormone therapy, radiation therapy are some ways of common adjuvant therapies.


3)Palliative Treatment:


The side effects that arise can be eliminated or relieved using palliative treatment.

Medications can relieve symptoms such as pain and shortness of breath. When a cure is not possible, surgery, radiation therapy, chemotherapy are used to relieve the symptoms and control the spread of cancer.


Modes of Treatment:


1) Surgery:  Helps remove cancer totally or partially

2) Chemotherapy: Uses medications and drugs to kill cancer cells

3) Radiation therapy: High powered energy beams such as protons or X-rays can be used to kill cancer cells.


Radiation therapy has two variations:


External Beam Radiation: Radiation from a machine outside the body

Brachytherapy: Machine is placed within the body


4)Bone Marrow Transplant/Stem Cell Transplant: Bone marrow is the material present within the bones that is responsible for the production of cells. A bone marrow transplant can involve cells from donors or from your own cells.

A bone marrow transplant involves the doctor using higher doses of chemotherapy to treat cancer. It can also be used to replace the diseased bone marrow.


5) Immunotherapy: Also known as Biological Therapy, takes the help of the body’s immune system to fight cancer. Cancer cells get lodged in the body only when the immune system does not see the cancer cells as an intruder.

Immunotherapy can further stimulate your immune system to detect and attack the cancer cells to remove cancer from the body.


6)Hormone Therapy: Certain types of cancers arise due to the effects of certain hormones in the body. For example, breast cancer and prostate cancer. Removal of these hormones from the body or at least blocking their effects can retard the growth of cancer cells.


7) Targeted Drug Therapy: Focuses on particular genes and proteins that allowed the cancer cells to survive and stay alive and target them.




1)Stop Smoking: Smoking is linked to not just lung cancer but various other cancers. Stopping smoking can reduce your chance of cancer by a large margin in the future.


2)Eat Healthy: Being overweight or obese can contribute to cancer. Regular exercise and maintaining a healthy diet can prevent obesity and lower your risk of cancer.


3) Exercise: Regular exercise is linked to a lower risk of cancer.


4) Avoid excess sun exposure: Sun rays contains ultraviolet rays which increases your chances of getting cancer. It is better to limit your exposure to the sun by not going out very often or at least applying sunscreen if you decide to go out.


5) Alcohol in moderation


6) Cancer Screening Tests


7) Immunization: Immunizations can protect you from those viruses which contribute to causing cancer for example hepatitis (Liver Cancer),  human papillomavirus (Cervical cancer), etc.




1) Cancer Screening:

Making a diagnosis for cancer or detecting cancer at the earliest is the key to cure cancer. Talk to your doctor about the available screening option that will help detect cancer at the earliest age and start treatment as soon as possible.


2) Cancer Diagnosis: 

A series of approaches are taken in order to diagnose cancer in a patient.


3) Physical Exam: 

Your doctor may try to feel any lumps in any part of the body that may indicate a tumour. During a physical exam, the doctor may look for abnormalities like enlargement of an organ or changes in the skin colour which may be indicative of potential cancer.


4) Laboratory Tests: 

Laboratory tests such as urine tests, blood tests can be used to detect abnormalities that can cause cancer in the long run. For instance, for a patient with leukaemia, a particular type of blood test called complete blood count is taken which reveals unusual types of white blood cells or unusual numbers of white blood cells.


5) Imaging Tests: 

This allows the doctor to examine bones and internal organs. Imaging tests may include computerized tomography scan (CT), bone scan, magnetic resonance imaging(MRI) ultrasound positron emission, tomography scan, x-ray, etc.


6) Biopsy: 

The most definitely give way to diagnose cancer, during a biopsy a doctor collects cell samples for testing in the laboratory.

B cells are then visualised with a microscope. Normal cells look uniform with the same sizes and are organised in a very orderly manner while cancer cells have varying sizes without a particular organisation and look without order.

Once the cancer is diagnosed the doctor will then try to determine the stage of cancer depending on which he will start the treatment.

Bones cans or exercise may be used to detect stages of cancer. Ages are indicated by the Roman numerals 0 to 4. Higher numbers indicate more dangerous stages and more intense treatment options.




1) Is cancer contagious? Will it spread from one person to another?

No, cancer does not spread from one person to another.


2)What are the different stages of a cancer cell progression?

Cancers generally occur in 4 stages. There are certain cases of Stage 0 as well.

  • Stage 0: This means, the cancer is present in the part of the body but has not spread to any other part of the body. Cancers during Stage 0 can be cured.


  • Stage 1: This stage of cancer represents a part of a tumour that hasn't gone very deep into tissues that are present nearby. It is also called Early Stage Cancer.


  • Stage 2 and 3: A stage where the tumour has gone deeper into the nearby tissues and may also have spread to the lymph nodes lying nearby (cancer cells travel to other parts of the body via lymph nodes). Cancer still has not yet gone to another body organ, it has just spread to nearby tissues and lymph nodes.


  • Stage 4: Known as Metastatic or Advanced Cancer, the tumour may have spread to other parts of the body during this stage. 


3) Does using Artificial Sweeteners lead to cancer?

Currently, there is no evidence that suggests artificial sweeteners causes cancer.

Abid Suhail

Abid Suhail

A medical student on the path to providing authentic medical knowledge for the sole purpose of generating awareness and education. More about me? I love Football :)