Cancer is medically known as malignant neoplasm or malignant tumor. It is characterized by abnormal or uncontrolled division & growth of cells, caused by pathological breakdown in the process of cell proliferation (Steward & Kliehues, 2003). The cells in our body grow normally and divide in a controlled way in order to keep the body functioning normal. When normal cells get damaged, they die, and new cells take their place. However, this process may go wrong to generate new cells even when the body doesn't need them, or that the damaged cells may not die the way they should. The growth of extra cells often forms a mass of tissue called a lump, growth, or tumor. Thus, tumor is an outcome of the process involving successive generations of cells, which progressively advance towards cancerous growth. All tumors increase in size. Some of them grow quickly & others grow slowly. The rate of progression of tumor is governed both by mutagenic agents (tumor initiators) and by non mutagenic agents (tumor promoters) that effect gene expression, stimulate cell proliferation and alter the ecological balance of mutant and non mutant cells. The cancer cells frequently move and break from site of the mass or tumor and enter into the bloodstream thereby spreading the disease to other parts of the body and this process is called metastasis (Steward & Kliehues, 2003).
Cancer is often defined as a disease that involves changes or mutations in the cell genome.
These changes (DNA mutations) produce proteins that disrupt the delicate cellular balance between cell division and quiescence; resulting in cells that keep dividing to form cancers (Hejmadi 2010).
Broadly, cancer can be grouped into following categories:
Carcinoma - cancer that begins i...
... middle of paper ...
...ased on demographic changes in populations using UN figures along with crude assumptions about the likely trends in incidence rates for six cancers (Bray, Jemal, Grey, et al., 2012).
5, 55000 people died because of cancer in India in 2010, according to estimates published in The Lancet today (March 28, 2012) (Dikshit., et al 2012). While as in Kashmir, 8648 patients were registered at Regional Cancer Centre (RCC), Sher-i-Kashmir Institute of Medical Sciences (SKIMS), Soura, Srinagar, from Jan 2009 to Dec 2011. Esophageal cancer was found to be the most common cancer followed by cancers of Lung, Stomach, Colorectal, Breast, Non-Hodgkin's Lymphoma, Gastro esophageal junction, Ovary, Skin, Gallbladder, Multiple Myeloma, Acute Lymphoid Leukemia, Urinary Bladder, Prostate and Hodgkin's lymphoma (Rasool , Lone , Wani, Afroz , Zaffar, Mohib-ul Haq 2012).
Note that the introduction of screening may produce short-term rises (AIHW, Cancer incidence projections) due to greater detection.
Malignant melanoma is a type of cancer arising from the melanocyte cells of the skin. The melanocytes are cells in the skin that produce the pigment melanin. Malignant melanoma develops when the melanocytes no longer respond to normal control mechanisms of cellular growth and are capable of invasion locally or spread to other organs in the body (metastasis), where again they invade and compromise the function of that organ.
..., while a cell undergoes cell cycle, when a cell comes in contact with another cell, it stops reproducing. However, cancer cells continue to duplicate repeatedly until there is a mass of cells or a tumor to form (see figure 9). Lastly, in cell division when there is a mutation or abnormality in the DNA, a normal cell stops dividing. However, a cancerous cell will continue to duplicate and form mutations (“Cell Biology and Cancer”). Also, cancer cells are harmful because they grow and duplicate with complete disregard to the functions and limitations of the body (see figure 10). Also, cancerous cells have the ability to spread through metastasis throughout parts of the body through the bloodstream. In terms of similar behavior to that of normal cells, cancerous cells also duplicate, but at a very different rate ("Cancer Cells vs. Normal Cells: What's Different?").
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.
The cell cycle is the process by which cells progress and divide. In normal cells, the cell cycle is controlled by a complex series of signaling pathways by which a cell grows, replicates it’s DNA and divides, these are called proto-oncogenes. A proto-oncogene is a normal gene that could become an oncogene due to mutations. This process has mechanisms to ensure that errors are corrected, if they are not, the cells commit suicide (apoptosis). This process is tightly regulated by the genes within a cell’s nucleus. In cancer, as a result of genetic mutations, this process malfunctions, resulting in uncontrolled cell proliferation. Mutations in proto-oncogene or in a tumour suppressor gene allow a cancerous cell to grow and divide without the normal control imposed by the cell cycle. A change in the DNA sequence of the proto-oncogene gives rise to an oncogene, which
According to “Medical News Today” cancer is a disease that is caused by an over growth of anomalous cells on one or more lungs. Cells often go up the air pipes which can cause difficulty to breath. Due to the over production of cells the tissue cells often begin to over produce; which results in tumors. There are two types of tumors: malignant and benign. Malignant tumors are the more dangerous of the two due to its invasive nature; which makes it cancerous. While benign is not invasive in other words non-cancerous. This is why cancer spreads to multiple areas and can be sometimes very difficult to fight. Cancer cells are abnormal not only because of their evasive nature, but also because of its irregular life cycle. Rather than expire like a regular cell, they continuously grow and duplicate which causes the disease to spread. This makes cell abnormal in shape and other qualities; known as a sickle cell. Due to the large growth and reproduction rate of the cells this makes the spreading of the cancer more rapid. Each cancer has specific symptom, for lung cancer the sympto...
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 ...
To begin, cancer starts to form when abnormal cells grow. Abnormal cells form when the DNA, is damaged. The fewer the amount of abnormal cells, the more treatable the cancer will be. In normal cells, the damaged DNA either gets repaired, or dies. In cancer cells, the damaged DNA doesn’t get repaired or dies like normal cells. The damaged cell instead replicates itself. It is difficult to understand exactly why or how cancer starts to grow, but common reasons can be from sun exposure or cigarette smoking. Cancer cells usually form a tumor. A type of cancer where a tumor doesn’t form is Leukemia. On the other hand, not all tumors are cancerous. There are benign and malignant tumors or masses. Benign tumors cannot spread to other organs of the body, but can be on the larger side and press on other organs. Benign tumors are not cancerous, but can still instill problems. Benign tumors can become malignant, or cancerous, after a period of time. Malignant tumors are the ones that are cancerous from the very beginning. This ...
Healthy cells grow and divide in a way to keep your body functioning properly. But when a cell is damaged and becomes cancerous, cells continue to divide, even when new cells aren't...
Cancer is a term used for diseases in which abnormal cells divide without control and begin to invade other tissues. The term cancer is also used when cells start to produce too quickly when there are not enough cells dying. Cancer cells are also called malignant cells. Cancerous cells are able to invade other healthy cells and can spread to other parts of the body through the blood and lymph systems.
An ordinary human body contains approximately one trillion cells and precisely 46 chromosomes in each cell. However, the human body can be altered by a genetic mutation. Over the course of history, genetic mutations have had a large impact on the human race. They have brought harm to numerous amounts of people. Cancer, in particular, is one of the most lethal diseases. Cancer begins when a portion of DNA inside a chromosome is damaged, causing a cell to mutate. Then, the mutated cell reproduces multiple times and creates a tumor. Afterwards, cancer cells break off of the tumor, enter the bloodstream, and disperse throughout the body. If the cells break off, the tumor is considered malignant - this type of cancer is very difficult to cure. Many patients today stay optimistic for a medication to heal cancer. It is imperative to address a few of the causes and effects of cancer in order to gain a general knowledge of genetic mutations.
The cancer cells from gene-mutation. Scientists now know some of the risk factors for lung cancer can cause certain changes in the DNA of lung cells. These changes can lead to not normal cell growth and, sometimes, cancer. DNA is the chemical in each of our cells that makes up our genes and how our cells function. People usually look like their parents because they are the source of our DNA. But DNA affects more than how we look; it also can affect our risk for developing certain diseases, including some kinds of cancer like lung cancer etc…Some people inherit DNA mutation from their parents that greatly increase their risk for developing certain cancers.
Over the past few decades, cancer has become a very prominent disease. There are many different types of cancer and many different causes of the the disease. Most cancers are caused by a genetic mutation. The most common type occurs when a cell is divided. Proto-oncogenes, which are alleles in normal cells, mutate to form oncogenes.
Since 1979 the diagnoses of cancer have gone up nearly 20% in a generation as there is more people smoking, drinking, obesity and unfitness (theguardian website, 2011, para. 1). There has been in increase of women with the diagnosis, the diagnoses have risen up by 50% (459 per 100,00), men have risen from 20,000 to 24,000 (the guardian website, 2011, para. 2). Socioeconomic class does have an effect in some cases as cervical and lung cancers are more common in poor people while rates of breast cancer and melanoma are higher in the wealthy (ScienceDaily website, 2008, para. 1). Demographics could also have some effect as those of the wealthier group have more exposure to UV by traveling abroad for the holidays (ScienceDaily website, 2008, para. 5). In regards to smoking, deprived groups continue to smoke while the wealthier groups have quit smoking (ScienceDaily website, 2008, para. 7). Researchers have linked cancer to not only demographics, socioeconomic class but also race and