Now let’s look at the second very important property of the cancer cells that is metastasis. In the first part of our Cancer Biology series, this property was introduced as – Unrestrained Spread. Stating that the cancer cells spread throughout the body in an unrestrained way.
Before we proceed, we recommend that you go through the part -1, part -2, and part -3, of this blog. This will help you understand the complete topic better and be ready for the next parts.
Basically, metastasis means spreading of cancer. And according to literature, research reports and classifications, cancer can be divided into two very important classes based on the property of metastasis:
- Benign Tumours – These are actually the localized tumours that do not leave their organ of origin. It means that they cannot spread cancer. So, it can be said that they are not showing metastasis.
- Malignant Tumours – These are the spreading tumours that can go to another organ from their organ of origin. It means they are showing the property of metastasis.
Basic Process of Metastasis
Let’s try to understand the basic process of metastasis through an example.
In the picture, you can see a primary tumour which is in its origin point and in the first step the tumour cells show local invasion. And they try to cross the wall of blood capillaries with a process which is called as intravasation. They flow through the blood capillary in the circulation. Then they show the property of extravasation and go to a new site and try to survive there. Here they can stay dormant for some time and finally create a new tumour.
So, this is the whole process of metastasis in a brief –
- Circulation movement
- Generation of a new tumour
Now you would be able to easily imagine that if a primary tumour, which is growing in a particular organ or a particular site has to start the process of metastasis or to go from one place to another place, it has to change its genetic programming and the cell interaction. Along with that, it must gain a new type of properties so it can flow through the circulation and ultimately it has to lose all those properties and it must start a new tumour.
Fundamentally, there are different mechanisms for explaining the process of metastasis and one of those is EMT – Epithelial-Mesenchymal Transitions.
In the part-5 of our cancer biology blog series, we will discuss the EMT process in detail. To read, part 5 – Click Here.