It involves genetic changes in a group of cells that causes them to grow and behave abnormally.
Tumorigenesis is another term used for this process.
What Is Cancer?
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To understand oncogenesis, it helps to understand what acancerreally is.
What Are Cells?
Cells are the small individual working units that compose the tissues and organs of your body.
Each cell contains its own copy ofDNA, the genetic material you inherit from your parents.
Different cells have different purposes and do different jobs, depending on where in the body they are found.
But this should happen only under specific, controlled circumstances.
Certain immune cells should replicate themselves as part of your immune response to infection.
But other cells in your body shouldnt replicate and divide under normal circumstances.
For example, muscle cells do not normally replicate themselves in adults.
Cancer can occur when a cell or group of cells begin toabnormally growand divide in an unchecked way.
Instead of dividing only when needed, they may begin to divide unnecessarily.
Then, daughter cells of the abnormal cells will share this same tendency to dividethis creates even more cells.
In some cases, the cancer cells may invade other areas and interfere with the functions of normal cells.
This can lead to the symptoms of the specific cancer, and it may cause death if untreated.
A very complicated system of signaling inside and outside cells triggers the process of replication (called mitosis).
There are many different important proteins that help regulate cell divisionthese are encoded by specific genes in your DNA.
Other important proteins work to help your cell recognize when it is busted normally.
Sometimes, the cell manages to repair the DNA successfully without a problem.
This mutation is then passed down to every new daughter cell.
The protein made from the mutated DNA may not work as it normally would.
These are called epigenetic changes.
Or it might do the reverse.
Depending on the gene involved, this might contribute to the process of oncogenesis.
It also may metastasize.
What Is the Difference Between a True Cancer and a Benign Tumor?
One important characteristic of a true cancer is this ability to invade nearby tissue or potentiallymetastasizethroughout the body.
Benign tumors share some characteristics with cancer.
They may have picked up some genetic hits that cause them to behave a little differently than normal tissue.
They may also divide in some uncontrolled ways.
However, they do not have as many severe genetic and epigenetic hits as a cancer.
By definition, a benign tumor is not prone to massive spread in the body.
However, some benign tumors still sometimes cause problems.
This might happen, for example, if one was pressing on a nearby important blood vessel.
What Causes Cancer?
Cancers are a complex group of diseases with a complicated set of causes.
Anything that can damage the DNA or cause certain epigenetic changes can increase ones risk of getting cancer.
Carcinogens
Such substances that can damage the DNA are calledcarcinogens.
DNA damage to specific genes can lead to the process of oncogenesis.
For example, excess exposure to ionizing radiation from the sun can increase ones risk of getting skin cancer.
Exposure to DNA-damaging substances in cigarettes can increase ones risk of lung and other cancers.
In most cases, its thought that a variety of factors must come together to cause a cancer.
In other words, a person must experience more than one genetic or epigenetic alteration to develop the disease.
These cells sometimes, but not always, go on to develop a cancer.
These viruses can insert genetic material into normal cells that can contribute to cancer development.
In other cases, they may disrupt the immune system, thus increasing ones risk of cancer.
Family History
Ones family history is also an important factor.
People who have inherited certain genes from their parents are more susceptible to getting cancer.
Thats because certain variants of particular genes may be more susceptible to cancer formation.
For example, theBRCA genemakes a protein that is important for normal DNA repair.
Age
Age is also a major risk factor.
Except for certain cancers that almost always occur in children, the risk of most cancers increases with age.
Thats because people normally accumulate mutations in their genes over time.
Many types of cancer treatments focus on removing cancerous cells from the body.
Other treatments, like chemotherapy, may focus on killing the cancerous cells.
Such treatments dont work by stopping oncogenesis, but by removing cancerous cells from the body completely.
However, other types of cancer treatments prevent cancerous cells from being as dangerous to the body.
For example, certain treatments stop the cancer’s ability to form new blood vessels (angiogenesis).
Other treatments may slow a cancers growth in other ways.
In this sense, these treatments may slow or even stop the process of oncogenesis.
However, most people will also need other treatments that directly remove the cancer from the body.
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