Cancer is a disease of Cell Division  
     
 

Cancer is the abnormal growth of cells during division.It is a name applied to around 100 diseases characterised by cellular division. There are many processes that control a cell’s growth and division, many of which can go wrong. As a general rule, several of these control mechanisms need to be damaged before a cell becomes cancerous.

Cancer usually results from defects or damage in one or more of the genes involved in cell division. If these genes become damaged, the defective cells can multiply to form abnormal tissue (tumor).  There are four main types of gene directly linked to cell division, most tumors, have damaged copies of more than one of these genes;

- Oncogenes (initiate cellular division)


- Tumor Suppressor genes (instruct the cells not to divide)


- Suicide genes (genes which terminate themselves, when they know the division process has gone wrong)


- DNA repair genes (Cells that repair other DNA)

 

 

 

During cell division, a cell makes an exact copy of itself (DNA Replication). In this process there is a step where one cell interacts to check if cell division is occurring correctly. The communication can be ‘out of phase’ with each cell, then they can sometimes mutate and become cancerous. Cell division involves hundreds of proteins (and therefore many genes).

Cancer is often perceived as a disease that strikes for no apparent reason. While scientists don't yet know all the reasons, many of the causes of cancer have already been identified. Besides intrinsic factors such as heredity, diet, and hormones, scientific studies point to key extrinsic factors that contribute to the cancer's development: chemicals, smoking, radiation, viruses and bacteria.

 

The Lymphatic System

The lymphatic system is an essential part of the immune system, which helps the body fight infections or cancers.  The lymphatic system consists of a network of vessels that drain tissue fluid (lymph) into lymph nodes, larger fluid-containing lymph ducts, and specialized organs involved in the immune system.  The lymph nodes and organs act as a type of “filter,” removing invading organisms or abnormal cells from the lymph fluid and “processing” them in a way that allows the body to fight these harmful agents.  Lymph is a clear whitish/yellowish fluid that contains white blood cells (lymphocytes), proteins, and some red blood cells.

 

The bean-shaped lymph nodes of the lymphatic system are connected by vessels.  Lymph nodes are usually present in clusters in the armpits, on either side of the neck, and in the groin.   The lymph nodes filter lymph fluid and trap foreign materials.  Any fluid absorbed by the lymphatic system passes through at least one lymph node before it returns to circulation. 

 


The lymph nodes contain lymphocytes (white blood cells) which help destroy foreign bacteria or other harmful cells.  The lymph nodes may become enlarged or swollen when they fight an infection since they must produce additional white blood cells. The lymph nodes may feel tender or inflamed as they are actively fighting a foreign body.  Sometimes, the lymphatic vessels will become visible as thin red lines along a limb as the result of an infection (known as lymphangitis).  Lymph nodes may also swell from the formation of an abscess (closed pocket filled with pus) in the nodes or if they contain cancer cells.