12 causes of Cancer.

How is Cancer caused?

We know that a complex disease like Cancer does not have 'one common cause' which is very simple, preventable, and easy to understand. For decades now,  researchers have been studying its cause , with a huge sum of money invested, using the best existing technology there is. And this has equipped us with the understanding of a  basic pathway that leads to Cancer. Let's have a look...

cancer cells spreading

Understanding basic pathway of cause of Cancer :
First of all, a single pathway for cause of cancer does not exist presently, and if it does, it's not yet found. But there are a few common sequential things that go wrong in and around a cell, which ultimately leads to cancer. So, lets take a look at those common factors.

• The one basic factor is, damage to the DNA or genetic blueprint of the cells, which causes mutation or sudden change.
• This change happens in the 2 genes that regulate the cell's multiplication as we discussed earlier, the proto-onco genes and the tumor suppressor genes.
• Now, not all types of damage to the DNA  will produce the same effect in these genes. That's how we get a variety of cancer types! 
• The specific thing that damages the DNA of a cell, often determines the type of Cancer. 
• For example, the damage caused to the cell because of carcinogen in tobacco and UV rays of the sun is very different. Each 'cause' or way of damage to a cell has a signature effect on the mutation of the cell, and hence produces a particular type of Cancer. The same applies to a virus that causes cancer as well.
• Now, is one mutation in one cell enough for producing cancer? No. It takes a series of mutations in that cell for it to undergo a cancerous change.
• This is the reason why Cancer does not happen after a year of smoking. It requires constant and long-term exposure to a carcinogen before cancer shows up. It waits for the body to become vulnerable and incapable of repairing the damage before it shows up!
• In case of familial cancers, they show up earlier than usual. The reason is that, the mutated genes are already present in that particular individual, inherited from the parents. So a little bit of exposure to the carcinogens is all it takes.

Apoptosis gone wrong :
Apoptosis is the self-regulation of cell growth, or a mechanism of natural cell death. Usually, when the cells are physically worn out, or genetically damaged, the undergo apoptosis, so that they are replaced by new normal healthy cells and the function of cells is not compromised. But when this process goes wrong, the genetically damaged cells continue to proliferate and become malignant.

Now that we have a basic understanding of what goes wrong, let's have a look at some common reasons WHY it does : 12 causes of cancer

1. Smoking or Tobacco chewing
2. Alcohol consumption
3. Betel nut
4. Sunlight exposure
5. Irradiation or radiation exposure
6. Irritants
7. Chemical Carcinogens
8. Hormonal imbalance
9. Viruses
10.Bacteria
11.Pre-existing genetic abnormalities
12.Faulty food habits

The 12 common causes of cancer will be discussed in detail in the further articles.

Also read
5 reasons why you should study Oncology.
Cancer and surgery.
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What is Cancer-related fatigue?
What is psycho-oncology?
12 causes of cancer.
Cancer in 21st century.