Hippocrates – the Father of Medicine was the first to use the term ‘karkinos’ (a Greek word which means crab) to denote tumours. It is postulated that this term was chosen due to the crab-like fingerous projections which spread from cancerous growths in the body. In addition, it is said that the tumours were hard to touch like the shell of a crab and the pain it causes is not less than the sharp pinch of a crab and these additional factors justified the name of this disease – ‘cancer’
Cancer is a term that strikes terror when heard and one of the most widespread diseases globally. Do you know what is this disease all about?
Cancer refers to a disease caused when some genes in the cells of the body run amuck. When a cell divides there are various genes which tightly control the same and keep the process in control. When these genes become faulty there is a higher prevalence of cancers. Each cell is equipped with an auto-destruct code which gets activated when cell division goes out of hand or when the cells become old and need to be replaced. When this auto-destruct code ceases to work, then cells do not die and adds on the pile of unwanted cells in the body.
There are strict checks in place for cell division as well and when these stop functioning, cells divide uncontrollably resulting in a mass of cells normally called as a tumour. Now, while you may wonder how this could be harmful since the more the cells, the better they function, let me clarify on the nature of these cells. Normal cells in the body, divide and produce daughter cells which then mature into functional cells. In cancerous conditions, while the cells do divide, they lose control over the stop of division and at the same time the daughter cells which are produced do not mature. Hence the outcome is a large mass of cells which are immature and hence do not function normally.
Some of these cancers are localized and hence can be treated fairly successfully. They are called benign local tumours. Some other types of cancer cells migrate via the blood or lymph to other parts of the body far away from its tissue of origin causing secondary cancers there as well. These cells are called metastatic cells and the process is called metastasis. These cancers are difficult to treat since they spread readily.
Like sentries, there are genes in the body which regulate the DNA replication process and thus play a role in the genetic aspect of cancer development. DNA repair genes and Tumour suppressor genes fall under this category. DNA or the fingerprint of life are the templates for making RNA which act as the messenger molecules with the code from which functional proteins are formed. The DNA repair genes serve to prevent any damages caused in the code during replication, and mutations in these DNA repair genes cause cells to generate additional mutations which can then develop into cancer.
In addition, genes called tumour suppressor genes control cell growth and division and suppress any changes which can develop into possible cancers. When these genes do not function efficiently due to mutations in them, there are higher probabilities of developing tumours as well.
These genetic changes lead to other molecular changes which then facilitates the development of cancers. They are primarily boosted by environmental factors like radiation, Ultraviolet rays, smoking etc.
Cancer cells are smart and they evolve ways to ensure that they evade the body’s surveillance and defense systems. They are known to induce blood vessel formation near them such that they get a limitless supply of blood with nutrients and oxygen for their survival. They also have been shown to bypass the immune cells which could weed them out once they detect these rogue cells.
While these are the factors known about cancers, there are a lot more unknown aspects and there are many groups across the world studying these cells and devising methods to root them out from the body.
To learn more on cancer:
https://www.cancercenter.com/what-is-cancer
https://www.cancer.gov/about-cancer/understanding/what-is-cancer