The Biology of Cancer
In this report I will discuss the biology of cancer, including the
explanations of what is cancer, what causes it and how it can be
prevented. In addition, I will briefly discuss the different ways it
is treated.
What is cancer?
Cancer develops when cells in a part of the body begin to grow out of
control. Although there are many kinds of cancer, they all start due
to the abnormal cells growing out of control.
Normal body cells grow, divide and die in an orderly fashion. Until a
person is an adult, the cells divide very rapidly, whereas after they
have become an adult, the cells in most parts of the body divide only
to replace worn out or dying cells and to repair injuries.
Cancer cells develop because of damage to DNA. Most of the time when
DNA is damaged, it dies or it is repaired whereas in cancer cells, it
is not repaired. People can inherit this damaged DNA and this accounts
for inherited cancers. Many times though, a person's DNA becomes
damaged because of the exposure to something in the environment, like
smoking. This is not an inherited factor.
Cancer usually forms as a tumour but some cancers like leukaemia
don't. Cancer cells usually travel to other parts of the body where
they begin to grow and replace normal tissue. This process is called
metastasis, and occurs as the cancer cells get into the bloodstream or
lymph vessels of our body. When cells from a cancer like breast cancer
spread to another organ like the liver, it is still called breast
cancer and not liver cancer.
Who gets cancer?
Over one million people get cancer each year. Anyone can get cancer at
any age; however, about 77% of all cancers are diagnosed in people
aged 55 or older. Today, millions of people are living with cancer or
have been cured of the disease. The sooner a cancer is found and the
sooner treatment begins, the better the patient's chances of a cure.
The cancer stem cell theory hypothesizes that tumors or cancers arise from mutations or epigenetic changes in normal stem cells. These mutated or genetically altered stem cells possess the properties of the normal stem cells such as the ability to self-renew, differentiate into any type of body cell, and resist apoptosis. Hence, the cancer stem cells (CSC) are named so. It is also suggested that because of the above-mentioned properties of the cancer stem cells, the current anti-cancer therapies are not entirely successful (Gil et al, 2008). Despite surgery and other therapies, even if very few of these cancer stem cells survive, they can continue to act as a source for more tumors, even though the therapies eliminate all visible signs of cancer.
Cancer is the term used to describe a group of diseases consisting of hundreds of ailments and although there exists so many different types of cancer, they all begin in a similar way. The body is made up of over a trillion cells, and cancer is the uncontrolled growth of malfunctioning cells in the body (Dawson, 1996). “Normal body cells grow, divide, and die in an orderly fashion. During the early years of a person’s life, normal cells divide faster to allow the person to grow. After the person becomes an adult, most cells divide only to replace worn-out or dying cells or to repair injuries” (American Cancer Society, 2012).
Cancer starts when cells in a part of the body start to grow out of control. Cancer cell growth is different from normal cell growth. Instead of dying, cancer cells continue to grow and form new, abnormal cells. Cancer cells can also invade (grow into) other tissues, something that normal cells cannot do. Growing out of control and invading other tissues are what makes a cell a cancer cell. Cells become cancer cells because of DNA (deoxyribonucleic acid) damage. DNA is in every cell and it directs all the cell’s actions. In a normal cell, when DNA gets damaged the cell either repairs the damage or the cell dies. In cancer cells, the damaged DNA is not repaired, and the cell doesn’t die like it should. Instead, the cell goes on making new cells that the body doesn’t need. These new cells all have the same abnormal DNA as the first cell does.
My sister, Kathy, was diagnosed with cancer in 2013. I was shocked because my sister was always the healthy one among all us girls, the type of cancer, Kathy called colon cancer, Cancer that forms in the tissues of the colon. Most oncogene mutations of indisputable normal genes designate proto-oncogenes. Proto-oncogenes determine the “excellent” genes that usually rule what cell do and the way typically it distribute. Once a factor mutates (changes) into cell, it come back a "hurtful" factor that may become usefulness on or activated once it's not believe to be. Once this occurs, the cell becomes out of management, which might pass to cancer. As scientists learn additional throughout oncogenes, they will be powerful to develop a medication that inhibits or restrain them.
Tumors are formed by the alteration of the body’s own cells. This can be caused by environmental factors such as radiation, like UV exposure, chemicals or viruses 1. These can disrupt genes that control growth and cause an increase in cell division and proliferation. Proto-oncogenes are those genes that control normal but essential cell processes that keep cell growth and death in check. Two important categories are apoptosis genes, which regulate cell death, and tumor suppressor genes, which decrease cell propagation 1 . If these genes were mutated to the point where they cannot produce a functioning protein, cell division would continue far past what it was supposed to and unhealthy cells would be allowed to live and continue to multiply. This is what creates a malignant tumor. Certain conditions in the body can also promote the growth of cancer cells. One of these is a deficiency of natural killer (NK) cells, which are able to kill cancer cells by creating a pore in the cell membrane with perforin and releasing granzymes into the cell. Low levels of perforin allow for tumor growth 1. Chronic inflammation can also ...
Today in the United States, Breast Cancer occurs in about one in eight women which is currently the most common cancer among women. The number of cases is expected to decrease due to the advancements in technology and dedicated researchers. Scientists have put an estimated 4.8 billion dollars towards the research every year to help find a cure or a new treatment for breast cancer ("STAT Facts Breast Cancer"). Researchers have found causes, put in research and theories that help with understanding treatments, prevention and also common symptoms and coping mechanisms.
Usually, normal cells die when they are old or damaged, newly grow cells will replace them. However, if something goes wrong, there may be too many new cells when the body only needs a few of them, and the body can’t get rid of old cells, it builds up a mass of tissue called tumor. There are two types of tumor, begin or malignant. Begin tumors are usually not harmful to human body, however, malignant tumors could be life threatening. This type of tumors will invade organs and tissues around them, travel through blood vessels or lymph vessels, attach to other tissues and destroy them. Malignant tumors arise in breast tissues and cause breast cancer.
25% of the deaths h in 1991 and is the most common cause of death
Cancer Cancer is a disease in which cells grow out of control and invade, erode, and destroy normal tissue. Damaged genes cause this development of cancer. These damaged genes are often a factor caused by such things such as the environment, and can be influenced by inherited factors. As the very early damaged cells divide they can evolve into a malignant cell population, and lose the control mechanism that govern normal cell division. These malignant cells can then go on to form solid tumours that start to destroy normal tissue.
“Since 1990, over 6 million Americans have died of cancer, more than the combined casualties from the Civil war, WWII, and the Vietnam and Korean conflicts combined” (Faguet, p. 5). According to American Cancer Society projections, there were 1,529,560 new cases of cancer in 2010. Cancer is becoming more and more common around the world. New cancers are constantly being discovered. Researchers are finding new ways to detect cancer and treat it so that the fatality rate does not rise. However, there are some cancers that researchers have not yet discovered a cure for. It is very important for Cancer Research to continue so that one day these cancers will no longer be a treat.
In contrast to the inward growth of a polyp, a true cancer can grow inward toward the hollow part of the colon or rectum, and/or outward through the wall of these organs. If not treated, cells from the tumor may break away and spread through the bloodstream or lymph system to other parts of the body. There, they can form "colony" tumors. This process is called metastasis.
Cancer occurs when cells divide uncontrollably. Cells keep dividing even though new cells are not needed. Change from normal to cancerous cells requires gene alterations. Altered genes and uncontrolled growth may lead to tumors.
Cancer is a disease that plagues our society, and is at the forefront of scientific research around the globe. There have been many advancements toward cancer research, and in the development of therapies or potential cures. However, cancer does remain one of the largest health issues to date. There are many unanswered questions about this disease, and even with extensive research, it usually leads to more questions. Cancer stem cells are a type of cancer cell that play an intimate role in determining the potential aggressive behavior of cancer. Cancer stem cells have taken the research world by storm, and although heavily debated, could potentially lead to the development of cancer therapies and impact the future of cancer treatment, or even a cure. In order to understand cancer stem cells, one must first understand stem cells in general. The idea of cancer stem cells was proposed over 100 years ago, but has recently become a major focus because of the similarities they share with normal stem cells. The idea of cancer stem cells generated research because sub-components of stem cells have been located in tumors of the breast, brain, and other organs. The parallels between cancer stem cells and stem cells have led to a cancer stem cell theory or hypothesis, and could one day hopefully lead to the eradication of cancer.
So picture yourself, your mother or father has just undergone cancer treatment and now you are afraid that the disease could be passed down to you. Now picture yourself in the alternative knowing that the disease can be based down to you and your offspring and there are effective treatments in place. These are the studies that are being done in evolutionary biology of cancer and scientists are making great progress. Ecology and Evolutionary Biologists claim that natural selection has a factor in the genetics of cancer. The theory of evolution, Darwinism, explains the idea that species by natural selection advance and others do not. To explain further an organism’s ability to survive, reproduce and pass their genes down to their offspring has to do with natural selection.3 This all cumulates into one must know their past to understand their future.
Cells are the basic unit of life that hold important information that make us who we are. In the human body there are many cells that make up how we act and look from the inside, out. Cells play a vital role because they can divide in many ways for a cell to function properly. Normal functioning cells and Cancer cells are two different cells that help understand the work behind their functions that occur in the human body. Normal functioning cells and Cancer cells both have similarities, differences and important components that are vital to the cell cycle that play a major role in the living human system.