What is a Tumour?
Every part of the human body is made up of cells. While the body is made up of different types of cells with different functions and in specific locations, they all have similar chemical and structural properties.
A typical cell consists of a membrane which holds the cytoplasm together and a nucleus inside the cytoplasm.
The nucleus is known as the command centre of the cell. It consists of DNA, in which the genes responsible for cell growth and cell reproduction are present.
Sometimes, when there are changes in the genes, the cells no longer receive information and start to grow, divide and multiply uncontrollably without specialization.
Soon, there will be a mass of disorganised cells forming a lump and this mass is called a tumour.
Genes and Mutation
We know that genes are responsible for controlling cell growth. In the event that they get mutated, it may lead to complications.
When these are in this functional and moderating stage, they are known as proto-oncogenes.
Once these get mutated, proto-oncogenes activate oncogenes. These new genes are responsible for the uncontrollable cell division.
Tumour Suppressor Gene
This gene is similar to the pro-oncogene. It is responsible for regulating cell growth, repairs any potential abnormalities in the functioning of the DNA and destroys unrequired excess cells.
When TSG undergoes mutation, it leads to the formation of tumours that form rapidly.
So in other words, inactivation of tumour suppressor genes and activation of oncogenes leads to cancer.
Now the interesting thing about mutation is that it could occur due to hereditary reasons or environmental factors like smoking or it could happen by chance during cell division.
This is also why when you continuously rub your tongue against a broken tooth, it could lead to oral cancer because the wounded tongue undergoes increased cell division and therefore, increasing the risk of mutation.
Credits : Wikimedia commons Caption : Comparison Between normal cell and mutated cancer cell
Classification of Tumour
They can be classified into three types:Benign Premalignant MalignantThey are non-cancerous tumours.They are a transition from non-cancerous to cancerous tumours.They are cancerous tumours.They cannot grow and spread to other parts of the body to form secondary tumours.They have potential to spread and grow very slowly. They grow rapidly and travel to other parts of the body, forming secondary and tertiary tumours.Can be surgically removed and the tumour will not grow back.Tumour may or may not grow back.After surgical removal, tumours can most possibly grow back even if one cancerous cell was left behind.
There are four types of benign tumours:
The are tumours that originate from the epithelial cells lining of important glands and other organ tissues.
They are most commonly found in the colon, thyroid, breast and adrenal glands.
It is known as fibromas and these tumour cells are found in connective tissues present in organs.
The most common types of fibroids are found in the uterus and can cause heavy bleeding and a lot of discomfort.
Fibroids are also found as bumps on the face and leg.
This type of tumour is caused from rapid and excessive buildup of blood vessels cells.
They appear on the surface of the skin in a bluish-red colour and are often mistaken as birthmarks.
The mutated cells in lipomas are fat cells that divide rapidly in the body. The tumours are soft and slow-growing. It is usually found in fatty areas like the arms, neck, shoulder and back.
Mutation is usually due to hereditary traits.
Most benign tumours are not dangerous and can be left alone. Some may even disappear.
However, in some cases, the tumour presses upon important nerve and blood vessels, causing serious damages like muscle loss, vision and auditory loss.
They also become painful.
This is when the condition must be treated either by shrinking the tumour with chemotherapy or through surgically removing the tumor.
Lastly, benign tumours must be closely monitored to ensure that it does not transform into premalignant and become cancerous.
Credits : unsplash Caption : Surgical removal of tumours
There are four types of premalignant tumours:
They are pre-cancer cells caused due to excessive exposure of the skin in sunlight. The UV light damages the skin cells and triggers them to multiply.
They have high potential to transform into squamous cell skin cancer.
This tumour is caused due to uncontrollable division of the abnormal cells in the lining of the cervix.
These cells are not cancerous but if left untreated, it transforms into cervical cancer in 10-25 years.
Cancerous cells originate from the glandular lining of the bronchi in the lungs.
Most commonly caused due to the body’s response to toxicity induced by smoking tobacco.
The tumours are in the form of white, thick patches that are most commonly found in the internal areas of the mouth like cheeks, gums and tongue.
The cause of leukoplakia is unknown but the use of tobacco seems to trigger the formation of this tumour and it can often lead to oral cancer.
Most premalignant tumours get transformed into cancer and therefore, it is advisable to treat these tumours surgically, or with laser or chemotherapy.
There are four types of malignant/cancerous tumours:
They are the most common type of malignant tumours and are formed from excess epithelial cell division in the skin and the tissue lining of organs.
They usually occur in the lungs, liver, stomach, breast and pancreas.
These cancerous cells originate from the connective tissues of cartilage, fats, bones, nerves and cells of the bone marrow.
They can be found in almost any part of the body and form a massive, painful lump.
Germ cell cancer
These cancerous cells originate from the germ cells in the ovaries and testes.. Germ cells are the cells that form the male and female gametes: the sperm and egg.
They are very dangerous as they often spread to the liver, lungs, lymph nodes and brain.
These tumours usually occur in the developing embryo in the uterus and also affect young children that are still growing.
In the embryo, they damage the precursor cell which is important for forming just about any part of the foetus.
In infants, the tumour affects the liver and nerve cells.
Treatment of Cancer
There are various forms of treatment for cancer but ultimately the most suitable method has to be decided by the doctor.
Surgery- Physical removal of the tumour and ensuring no cancerous cell is left behind as it would only divide, leading to reformation of the tumour.
Radiation therapy – It is a process in which high dosage of radiation is used to kill cancer cells, shrink or stop its growth. However, there are a lot of side effects with radiation therapy.
Chemotherapy – It is similar to radiation therapy as it shrinks or kills cancerous cells. The only difference is that it is done by the use of drugs and not radiation.
Credits : Unsplash Caption: chemotherapy
Immunotherapy – It is a procedure in which substances extracted from organisms are used to treat cancer by boosting immunity and increasing the production of immune cells that targets cancerous cells by destroying them and preventing growth.
There are proteins that control the growth, division, spread and nature of tumour cells.
Target therapy is a method in which drugs are used to target and curb the action of these proteins and stop abnormal cell division. They also guide the antibodies to the site of the tumour that is to be destroyed.
It stops and prevents the growth of tumours by the use of hormones.
Moreover, this therapy also reduces cancer symptoms and eases pain that a patient would usually suffer. It is commonly practiced alongside radiation therapy.
Stem cell transplant
During radiation or chemotherapy, a lot of blood forming stem cells in the bone marrow gets destroyed.
These cells are very important for the production of red blood cells, white blood cells and platelets which are important for oxygenation, immunity and blood clot formation in the body.
Thus, new stem cells are restored in the body to make up for the loss.
Diagnosis And Detection Of Tumours
All types of tumours can be detected in the following ways :
Tumour Markers Test
The biology of the human anatomy was designed in such a way that whenever it detects something out of order, it tries to send signals.
Tumour markers are essential based on this principle.
They are substances like proteins that are produced in the blood, urine and tissues of the body in response to tumour formation in the body. They are usually made from a healthy cell or cancerous cell.
During this time, the production of these substances gets elevated and can be easily detected during diagnosis of blood or urine samples.
Till date, there has been no ” universal” marker that detects any type of cancer in the body. Each type of tumour has different markers, meaning they are extremely specific in nature.
Not only are they of great use in detecting cancer but also help the doctors decide the course of treatment and predict treatment, recovery and the probability of recurrence.
The only downside to tumour markers is that they may not show high levels until the condition is at its chronic stage. Moreover, due to its specific nature, multiple tests will have to be performed to confirm that the patient is cancer-free.
Credits: unsplash Caption: Tumor Marker test on blood
It is an imaging test that shows the exact location of the tumour and is also known as sonography.
This machine is based on a principle of sound echo. It uses high frequency sound waves and forms an image based on its reflection.
Ultrasound tests are usually performed by a doctor or sonographer in the hospital.
It is the method of extracting the patient’s tissues and sending it to the laboratory to test the presence of cancerous cells under the microscope.
There are various ways to extract tissues including the use of needles, skin shavings, bone marrow extraction etc
In this test, samples of cervical cells are taken and observed for detection of early mutations in the cell that could lead to cervical cancer.
This early test is taken to avoid or detect cervical cancer when it is at its most treatable stage.
The magnetic resonance imaging is used to detect the nature, size, location and monitor the progress of the tumour.
It is similar to the ultrasound test but uses magnets and radio waves instead.
One advantage of MRI is that it does not use X ray waves and is very safe, especially for pregnant women.
This test detects problems with the muscles, rhythm and valves of the heart without being invasive.
It is like the ultrasound of the heart and uses the echo of waves for the purpose of imaging.
EKG is also known as echocardiogram.
Credits: unsplash Caption: CT scan
The computed tomography scan is used in forming an image of the insides of a person’s head in a three dimensional graph, with the use of X rays.
A method which allows the doctor to examine the insides of a patient’s body. An endoscope is a thin and flexible tube which is attached to a small camera at one end.
The doctor typically inserts it into the person’s mouth, passing through the throat and esophagus.
This test is based on the principle of nuclear science. During this procedure, a substance that is radioactive in nature is injected into the bloodstream of a person.
After some few hours the entire body will be scanned for the radioactive substance, the areas in which the bone has absorbed the tracer in either very small or large amounts is most probably cancerous.