Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Cancer is a very complicated disease characterized by uncontrolled, unregulated cell growth.
Cancer is what happens when one of the cells in the body “forgets” that it’s supposed to be part of a multicellular organism, and starts acting like one of its single cell organism ancestors instead. Rather than performing a specific role that benefits the organism as a whole, it acts selfishly, evolving to produce as many offspring as it possibly can, and undergoing mutation and natural selection to evade the body’s attempts to eliminate the disease.
The process starts when a cell picks up a mutation in a gene that controls cell division. The cell passes the mutation on to all its progeny; more mutations start to accumulate as the cells divide faster and faster. The group of tumour cells behave and evolve like a colony of bacteria, or other single cell organisms; the forces of natural selection allow the cells best able to survive the body’s attempts to control them to predominate.
The cells that can divide the most often produce the most “offspring”; some cells in the tumour mass develop the ability to escape their location and colonize new environments around the body; some cells develop resistance to drugs, or to the body’s immune system. It really is just like a bacterial infection within the body, except that the “bacteria” are the body’s own cells – similar enough to normal cells that it’s incredibly difficult to kill the cancer cells without killing normal cells, but different enough that they can overcome and kill the entire organism. This is why it’s so difficult to treat, especially once the cells have started to spread around the body.
The formation of a cancer tissue can be roughly classified into 5 stages that are tightly controlled: 1. the birth of a cancer cell; 2. a game of survival; 3. a game of hanging on: colonization into a cell clump; 4. winning out and the formation of a malignant tumor; 5. the final blow: metastasis.
1. The birth of a cancer cell: the first step onto this long, ominous journey is genetic mutations.
Of a total of ~ 20,000 genes in our body, ~ 100 genes are known to directly affect the birth of a cancer cell. Overall, it requires at least two independent mutations in two classes of these 100 genes to make a cancer cell: one in the category called proto-oncogenes (Oncogene), whose mutations enhance the transition from a normal cell to a cancerous one; the other mutation in the category called tumor suppressor genes (Tumor suppressor gene).
So you can see the cancer cell as an anomaly caused by an aberrant core (genes).
There are three main ways that result in aberrant genes:
a. hereditary, in which the faulty genes are passed from one’s ancestors. A relatively well-known example is the BRCA mutations involved in breast cancer.
b. spontaneous mutations caused by the built-in mechanisms through which our DNA is replicated each time a cell divides. This happens much more often than one expects. In fact, it is estimated that in every cell of the new generation ~ 60 new mutations (called somatic mutations, Mutation rate) will happen in a cell’s genome.
However, the vast majority of such mutations are harmless — only the very rare ones that affect the activities of the oncogenes will result in the birth of the cancer cells.
c. “catalyzed” mutations caused by environmental factors such as radiation (UV, X-ray, and others), toxic chemicals such as tobacco and pollutions, and certain viruses.
All those external risk factors do one thing in terms of carcinogenesis, which is to greatly enhance the mutation rates during cell replication. In the case of a virus such as a human papillomavirus (HPV) which causes cervical cancer, the mutation rates in oncogenes are drastically increased.
Overall, a double-hit in the categories of oncogenes is the most important determinant factor that results in the birth of a cancer cell, although not necessarily the sole one. As described above, the birth of a single cancer cell happens much more often than one might expect. However, by no means does it have an easy life to live, and the chance of its winning out is still very, very slim at this stage (under normal circumstances).
2. A game of survival
Now in an ocean of normal cells and other natural defenders in the body, there is a lonely cancer cell that needs to first hang on for its life. Although the genetic mutations give it more power in terms of lifespan and proliferation, they also bring other significant obstacles for its life.
Believe it or not, the beginning of a cancer cell’s life is rather tough. Just like all natural ecological systems, in the human tissue environment this abnormal cell has to compete for nutrients, adapt to an environment that may not favor its survival, and evade the natural killer — the immune system.
As a result, the vast majority of newborn cancer cells die before they even have a chance to reproduce.
Correspondingly, many internal and external factors kick in at this step in terms of cancer development, which could be affected by one’s life style, further decreasing the chance of carcinogenesis.
Examples include: a. natural body metabolism and integrity. The more healthy and robust of one’s normal cells, the less likely a cancer cell will be able to survive, simply because of the power-imbalance. b. the surrounding micro-environment that could be affected by metabolism, cell-cell interactions, human microbiota (Microbiota), etc. For example, the cancer cell may prefer a different PH, or oxygen concentration, etc. Thus keeping a healthy microbe population is also beneficial for fighting against cancer. c. The killing machine, the immune system.
3. A game of hanging on
Once a cancer cell beats all the odds and survives, it will employ its most powerful weapon – fast replication – and starts proliferating.
However, at this step, the cancer cells are still outnumbered. In addition, since there are only a few of them, they are still trying to adapt to an unfavorable environment rather than building their own fortress. It’s still weak, and all the factors described in 2. (A game of surviving) could still eradicate them.
Thus it’s never too late to adopt a healthy habit, such as quitting smoking, starting to boost immunity, adapt to a more healthy diet, etc. By doing so you may just give your body the extra power it needs to get rid of those budding malignant cells.
4. The winning out phase
Only at this phase cancer cells really become dangerous. Now that the cancer cells have defeated a number of obstacles and outcompeted the normal cells, they start to proliferate at a crazy rate. In addition, since there are a large number of them, they start to connect to each other and change the micro-environment to their favor.
At this step one’s own defense system is not enough to handle the insults. But still, since the cancer cells just build one solid foundation in one area, they are still prone to be defeated by additional reinforcement, such as surgery and a series cancer therapies. That is why the earlier they are detected, the easier it is to destroy.
5. The final blow: metastasis
This is the final tipping point beyond which there is less hope of returning. The final blow of a cancer tissue is its migration. By doing so the most robust and devastating malignant cells are starting building their fortresses in other areas of the body, which are typically vital organs.
Yet even in this step there are still ways to deal with them. The most powerful weapon is still one’s own immune system, which is what the recent highly promising immunotherapy is based on.
In all, the majority of a cancer cell’s (tough) journey is just like that. Despite the notorious name it has, there are really numerous steps that it can be beaten. And the first step always starts with a balanced healthy life style.
treatment options
- Surgery: The goal of surgery is to remove the cancer or as much of the cancer as possible.
- Chemotherapy: Chemotherapy uses drugs to kill cancer cells.
- Radiation therapy. Radiation therapy uses high-powered energy beams, such as X-rays or protons, to kill cancer cells. Radiation treatment can come from a machine outside your body (external beam radiation), or it can be placed inside your body (brachytherapy).
- Bone marrow transplant: Your bone marrow is the material inside your bones that makes blood cells from blood stem cells. A bone marrow transplant, also known as a stem cell transplant, can use your own bone marrow stem cells or those from a donor.A bone marrow transplant allows your doctor to use higher doses of chemotherapy to treat your cancer. It may also be used to replace diseased bone marrow.
- Immuno therapy: Immuno therapy, also known as biological therapy, uses your body’s immune system to fight cancer. Cancer can survive unchecked in your body because your immune system doesn’t recognize it as an intruder. Immunotherapy can help your immune system “see” the cancer and attack it.
- Hormone therapy: Some types of cancer are fueled by your body’s hormones. Examples include breast cancer and prostate cancer. Removing those hormones from the body or blocking their effects may cause the cancer cells to stop growing.
- Targeted drug therapy: Targeted drug treatment focuses on specific abnormalities within cancer cells that allow them to survive.
- Cryoablation: This treatment kills cancer cells with cold. During cryoablation, a thin, wandlike needle (cryoprobe) is inserted through your skin and directly into the cancerous tumor. A gas is pumped into the cryoprobe in order to freeze the tissue. Then the tissue is allowed to thaw. The freezing and thawing process is repeated several times during the same treatment session in order to kill the cancer cells.
- Radio frequency ablation: This treatment uses electrical energy to heat cancer cells, causing them to die. During radio frequency ablation, a doctor guides a thin needle through the skin or through an incision and into the cancer tissue. High-frequency energy passes through the needle and causes the surrounding tissue to heat up, killing the nearby cells.
Since there are many aspects for causes of cancer all we can do is leading a healthy and disciplined lifestyle with a positive attitude is the best way to deal with cancer.
Eduindex 
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