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What Is Cancer? Essay, Research Paper
What is cancer? Cancer is the abnormal and uncontrolled growth of cells that if left untreated can ultimately cause death. The word cancer came from the Greek word for crab, karkinos. The early Greek physicians who first described cancerous tumors had no notion of their cause or true nature, but they were struck by the resemblance if some invasive tumors to crabs: a hard mass with a claw like extensions and an aggressive nature. Cancer causes about 550,000 deaths a year. Although many people believe that cancer is one disease, there are actually in fact over a 100 different forms of cancer. Some cancers can be cured, but not all of them have cures. Even though each type has its own characteristics, all cancers share one common characteristic, and that is the abnormal cell growth. These abnormal cells form tumors that invade normal tissues and disrupt body functions. Tumors are cancerous when they spread to other parts of the body. These types are called malignant, while tumors that do not have the potential to spread are called benign.
Benign tumors are made up of cells similar to the surrounding normal cells and are enclosed in a membrane that prevents them from penetrating the neighboring tissues. They are dangerous only if their physical presence interferes with body functions. For example, if a benign tumor grows in the brain and blocks the flow of blood to the brain, that can kill a person. To find out what kind of tumor that the person might have, the doctor will either do an X ray or a biopsy. If the tumor shows to be benign they might leave it or they might choose to remove it. But, if it shows to be a malignant tumor, more drastic steps are taken to get rid of the tumors. In this paper I will talk about some forms of cancer, there are to many to talk about them all so the ones I have choose to in form people about are: Breast Cancer, Lung Cancer, and skin cancer also known as melanoma.
The first form of cancer I am going to talk about is Breast Cancer. This is one of the most common cancers found in women and also has caused almost the same amount of deaths in women as lung cancer. Breast cancer can also occur in men, but it rarely does. In the United States, about one out of every nine women will develop breast cancer during her lifetime. Breast cancer increased during the 1980’s but now appears to have leveled off; each year about 175,000 American women are diagnosed with breast cancer. Although death rates declined during the early 1990’s, about 44,000 women die from breast cancer each year. Less than 1% of breast cancer cases occur in women under the age of 30, but a women’s risk doubles every 5 years between the ages of 30 and 45 and then increases by 10-15% every 5 years after the age 45. More than 75% of breast cancer is diagnosed in women over 50.
**”The way breast cancer behaves varies greatly. Cancer may stay confined to the breast for years, or it might spread to the nearby lymph nodes or even more distant areas before there is even a detection of a lump. The most common type of early breast cancer begins in the cells lining the ducts of the breast. The ducts connect the milk-producing glands to the nipple. Less often, cancer begins in milk-producing tissue, which is made up of lobes and smaller sections called lobules. Breast cancer falls into these categories based on its location and how it spreads:
? Early- This cancer is confined to the ducts or lobules. It’s curable more than 95 percent of the time. Even though a tumor is removed, however, there’s a small chance cancer cells have already spread.
? Invasive- This cancer has spread beyond ducts or lobules into surrounding breast tissue and perhaps nearby lymph nodes. Detection of a hard lump in your breast may be the first sign of invasive cancer. Most breast cancers have been present for several years before you can feel a lump.
? Metastatic- This is cancer that has spread to other parts of your body, such as distant lymph nodes, bones, lungs, liver or brain.
Some signs and symptoms of breast cancer may include:
? Clear or bloody discharge from your nipple
? A lump or thickening in your breast, which may not be painful or even tender
? Retracted nipple
? A change in the size or contours of your breasts. One breast may appear higher than the other, for example.
? Any flattening or indentation of the skin over your breast
? Redness or pitting of the skin over your breast, like the skin of an orange
The American Cancer Society estimates that 75% of breast cancer cases occur in women with no known high-risk factors. However, most experts agree that some factors may significantly increase your risk of breast cancer:
? Age- Your risk increases with your age.
? Country of birth- Breast cancer rates varies widely depending on where you were born. Rates are highest in North America and northern Europe, intermediate in southern Europe and Latin America, and lowest in Asia and South America.
? Family history- An inherited tendency to develop breast cancer accounts for about 5 percent to 10 percent of cases. If you have a strong family history of breast cancer, your chance of developing breast cancer may be as high as 1 in 2. Defects in either of two genes – BRCA1 and BRCA2 – increase your risk of inherited forms of breast cancer.
Both men and women can inherit and pass on defective BRCA genes. Families in which breast cancer is inherited typically demonstrate the following characteristics:
? Breast cancer in two or more close relatives, such as a mother and two sisters
? Early onset of breast cancer in family members, often before age 50
? History of breast cancer in more than one generation
? Cancer in both breasts in one or more family members
? Frequent occurrence of ovarian cancer
? Ashkenazi (Eastern and Central European) Jewish ancestry, with a family history of breast cancer or ovarian cancer or both
Breast cancer in several members of your family, especially if the disease occurs late in life, may be due merely to chance. Breast cancer is so common that random nonhereditary breast tumors may appear in more than one member of your family. It doesn’t necessarily mean that your family members have inherited an abnormal gene that predisposes them to cancer.
There are treatments for all patients with breast cancer. Four types of treatment are used:
? Surgery (taking out the cancer in an operation)
? Radiation therapy (using high-dose x-rays to kill cancer cells)
? Chemotherapy (using drugs to kill cancer cells)
? Hormone therapy (using drugs that change the way hormones work or taking out organs that make hormones, such as the ovaries)
? Biological therapy (using the body’s immune system to fight cancer), bone marrow transplantation, and peripheral blood stem cell transplantation are being tested in clinical trials.
Most patients with breast cancer choose to have surgery to remove the cancer from the breast. Some of the lymph nodes under the arm are also taken out and looked at under a microscope to see if there are any cancer cells.
Different types of operations used:
Surgery to conserve the breast:
? Lumpectomy (sometimes called excisional biopsy or wide excision) is the removal of the lump in the breast and some of the tissue around it. It is usually followed by radiation therapy to the part of the breast that remains. Most doctors also take out some of the lymph nodes under the arm.
? Partial or segmental mastectomy is the removal of the cancer as well as some of the breast tissue around the tumor and the lining over the chest muscles below the tumor. Usually some of the lymph nodes under the arm are taken out. In most cases, radiation therapy follows.
Other types of surgery:
? Total or simple mastectomy is the removal of the whole breast. Sometimes lymph nodes under the arm are also taken out.
? Modified radical mastectomy is the removal of the breast, many of the lymph nodes under the arm, the lining over the chest muscles, and sometimes part of the chest wall muscles. This is the most common operation for breast cancer.
? Radical mastectomy (also called the Halsted radical mastectomy) is the removal of the breast, chest muscles, and all of the lymph nodes under the arm. For many years, this was the operation most used, but it is used now only when the tumor has spread to the chest muscles.”
*** All of the above information was found on the AOL Health website including information from 2000 Mayo Foundation for Medical Education and Research, and was quoted directly from this web site.
Radiation therapy when high-energy x-rays are used to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body called external radiation therapy or from putting materials that produce radiation called radioisotopes through thin plastic tubes into the area where the cancer cells are found. This is called internal radiation therapy.
Chemotherapy is the use of drugs to kill cancer cells. Chemotherapy may be taken by mouth or it may be put into the body by inserting a needle into a vein or muscle. Chemotherapy is called a systemic treatment because the drugs enter the bloodstream, travel through the body, and can kill cancer cells outside the breast area.
If tests show that the breast cancer cells have estrogen receptors and progesterone receptors, hormone therapy may be given. Hormone therapy is used to change the way hormones in the body help the cancer grow. This can be done by using drugs that can change the way hormones work or also by surgery to take out the organs that make the hormones, such as the ovaries. Hormone therapy with tamoxifen is often given to patients with early stages of breast cancer. Hormone therapy with tamoxifen or estrogens can act on cells all over the body and may increase the chance of getting cancer of the uterus. A doctor should be seen for a pelvic examination every year. Any vaginal bleeding, other than menstrual bleeding, should be reported to a doctor as right away. Even if the doctor removes all the cancer that can be seen at the time of the operation, the patient may be given radiation therapy, chemotherapy, or hormone therapy after surgery to try to kill any cancer cells that may be left. Therapy given after an operation when there are no cancer cells that can be seen is called adjuvant therapy. Biological therapy tries to get the body to fight cancer. It uses materials made by the body or made in a laboratory to boost, direct, or restore the body’s natural defenses against disease. Biological therapy is sometimes called biological response modifier therapy or immunotherapy. This treatment is currently only being given in clinical trials.
Bone marrow transplantation is another type of treatment that is being studied in clinical trials also. Sometimes breast cancer becomes resistant to treatment with radiation therapy or chemotherapy. Very high doses of chemotherapy may then be used to treat the cancer. Because the high doses of chemotherapy can destroy the bone marrow, marrow is taken from the bones before treatment. The marrow is then frozen and the patient is given high-dose chemotherapy with or without radiation therapy to treat the cancer. The marrow that was taken out is then thawed and given back to the patient through a needle inserted into a vein to replace the marrow that was destroyed. This type of transplant is called an autologous transplant. If the marrow that is given is taken from another person, the transplant is called an allogeneic transplant.
Another type of autologous transplant is called a peripheral blood stem cell transplant. The patient’s blood is passed through a machine that removes the stem cells which are immature cells from which all blood cells develop and then the blood is returned back to the patient. This procedure is called leukapheresis it usually takes 3 or 4 hours to complete. The stem cells are treated with drugs to kill any cancer cells and then are frozen until they are transplanted back into the patient. This procedure may be done alone or with an autologous bone marrow transplant. There is a greater chance for recovery if the doctor chooses a hospital that does more than five bone marrow transplantations per year.
Lung Cancer is the most common cause of cancer death in the United States; it is responsible for about 160,000 deaths each year. For over 40 years, breast cancer was the major cause of death in women, but since 1987, lung cancer has surpasses breast cancer as a killer of women. Lung Cancer is the uncontrolled growth of abnormal cells in the lung. Normal lung tissue is made up of cells that are programmed by genes to create lung tissue in a certain shape and to perform functions. Lung cancer forms when the genetic material responsible for the production of lung cells is damaged. Repeated exposure to carcinogens such as tobacco smoke may cause damage in the lung cells. While tobacco, is the leading cause of lung cancer, some other carcinogens linked to lung cancer includes radon and asbestos.
Researches have discovered that there are some genes that are not replicated in the lung cells of people who smoke. This is known as gene deletion. It is especially prevalent in youth who smoke. Research indicates that young smokers are more susceptible to genetic damage in their lungs from tobacco smoke. Some genes are known as tumor suppressers. Their job is to keep abnormal cells form growing and forming tumors. Researchers have determined that a tumor suppresser gene known as p53 is almost always defective in cases of small cell lung cancer, and in approximately half of nonsmall cell lung cancer cases. Because of the defect in the gene, it does not stop the reproduction of tumor cells as it should. Some people inherit genes from their parents that are more resistant to damage and cancer than others. Those whose genes do not provide as much protection against cancer are said to be genetically susceptible to the disease. There are scientists working to understand the genetics involved in lung cancer. Researchers have shown that some cancers involve genes that are passed down from parents to their children, but the link to heredity has not been absolutely confirmed in lung cancer.
Lung cancer is one of the most common cancers in the United States. It represents about 15% of all cancer cases as of 1997. Lung cancer accounts for over one-fourth of cancer deaths in the United States It is the number one killer by cancer, it in fact kills more people than colon, prostate and breast cancer combined. At this time, over half of the lung cancer cases in the United States are in men, but the number of women diagnosed each year is increasing and will soon equal that in men. Today more women die of lung cancer than of any other cancer, and lung cancer also kills more men than any other cancer.
There are two major types of lung cancer. One is non-small-cell, which is about 80% of all the cases, and small-cell, which is about 20% of all the cases. The names refer to the kinds of cell that make up the tumor rather than the size of the tumor. Non-small-cell lung cancer is classified into three subtypes: adenocarcinomas, which are found in the mucus glands, squamous or epidermoid carcinoma which is located in the bronchial tubes, and large-cell carcinoma is found near the surface. Most of the cases of lung cancer begin in one lung. If left untreated it can spread to lymph nodes or other tissues in the chest, including the other lung. Lung cancer can spread throughout the body, to the bones, brain, liver, or other organs
The signs or symptoms of lung cancer could take years to appear and are at times confused for a less serious illness. Some symptoms or signs may not appear until in and advance stage of the disease. Some symptoms include; changes in a “smokers cough”, change in color or sputum, Persistent chest, shoulder, or back pain unrelated to pain from coughing, blood in sputum, recurrent pneumonia or bronchitis, and wheezing. There are also some signs and symptoms of lung cancer that may not be respiratory such as; fatigue, loss of appetite, headache, bone pain, aching joints, bone fractures not related to injury, and others.
*** (The following has been taken word for word from Lung Cancer Patent Overview 101Pamplet)
There are three main ways to treat lung cancer, and they are surgery, chemotherapy and radiation therapy. There have also been other new treatment options that have increased lung cancer survival rates significantly over the past few years.
? Surgery: operation to remove tumor (and surrounding tissue, section or entire lung)
? Chemotherapy: treatment with anti-cancer drugs to shrink or destroy tumor
? Radiation therapy: treatment using high-energy rays (X-rays, radium, neutrons) targeted to cancerous tumors
Non-Small-Cell Lung Cancer
Stage Description Treatment Options
STAGE I A/B Tumor of any size found in the lung only Surgery
STAGE II A/B Tumor has spread to lymph nodes associated with the lung Surgery followed by chemotherapy
STAGE III/A Tumor has spread to lymph nodes in the tracheal area, including chest wall and diaphragm Chemotherapy followed by radiation or surgery
STAGE III/B Tumor has spread to lymph nodes on opposite lung, or in the neck Combination of chemotherapy and radiation
STAGE IV Tumor has spread beyond the chest Chemotherapy and/or palliative care
Small-Cell Lung Cancer
Stage Description Treatment Options
LIMITED Tumor found in one lung and in nearby lymph nodes, and amenable to radiation Chemotherapy and radiation
EXTENSIVE Tumors spread beyond one lung or to other organs Chemotherapy
In the 1990s, new cancer drugs used in combination were found to be more successful and seemed to cause fewer side effects. There are newer treatments in development show promise of further improving lung cancer survival rates, as well as patients’ quality of life. These include:
? New chemotherapy regimens (altered dosage, timing, and sequencing of drugs)
? Monoclonal antibodies (engineered antibodies that target specific cancer proteins)
? Photodynamic therapy (combination treatment with chemicals and light)
? Anti-angiogenesis agents (drugs that inhibit blood vessels that feed tumors)
? Lung cancer vaccines (treatment to stimulate effective immune response)”
Melanoma is the most serious form of skin cancer. If diagnosed and removed while it is still small and limited to the outermost skin layer, it is almost 100% curable. Once it advances and spreads to other parts of the body, it is hard to treat and can become deadly. During the past 10 years the amount of cases of melanoma has increased more rapidly than that of any other cancer. Nearly 42,000 new cases are reported each year, and it is probable that a great many more occur and are not reported. Melanoma is a malignant tumor that originates in melanocytes, the cells that produce the pigment melanin that colors our skin, hair, and eyes and is heavily concentrated in most moles. The majority of melanomas, are black or brown. But melanomas occasionally stop producing pigment. When that happens, the melanomas may no longer be dark, but are skin-colored, pink, red, or purple.
Melanomas fall into four basic categories. Three of them begin in situ and sometimes become invasive. The fourth however is invasive from the start. It is helpful to recognize the names and be able to define the characteristics of each type. Superficial spreading melanoma is by far the most common type accounting for about 70 percent of all cases. As you might expect, this melanoma travels along the top layer of the skin for a fairly long time before penetrating into the skin. The first sign is the appearance of a flat or slightly raised discolored patch that has irregular borders and is somewhat geometrical in form. The color varies, and you may see areas of tan, brown, black, red, blue, or white. Sometimes an older mole will change in these ways, or a new one will arise. The melanoma can be seen almost anywhere on the body, but is most likely to occur on the trunk in men, the legs in women, and the upper back in both. Most melanomas found in the young are of the superficial spreading type. Lentigo maligna is similar to the superficial spreading type, as it also remains close to the skin surface for quite a while, and usually appears as a flat or mildly elevated mottled tan, brown, or dark brown discoloration. This type of in situ melanoma is found most often in the elderly, arising on chronically sun-exposed, damaged skin on the face, ears, arms, and upper trunk. Lentigo maligna is the most common form of melanoma in Hawaii. Lentigo maligna melanoma is the invasive form. The third type of melanoma, acral lentiginous melanoma, also spreads superficially before penetrating more deeply. It is quite different from the others, though, as it usually appears as a black or brown discoloration under the nails or on the soles of the feet or palms of the hands. This type of melanoma is sometimes found in dark-skinned people. It is the most common melanoma in African-Americans and Asians, and the least common among Caucasians. Unlike the other three types, nodular melanoma, is usually invasive at the time it is first diagnosed. The malignancy is recognized when it becomes a bump. The color is most often black, but occasionally is blue, gray, white, brown, tan, red, or skin tone. The most frequent locations are the trunk, legs, and arms, mainly of elderly people, as well as the scalp in men. This is the most aggressive of the melanomas, and is found in 10 to 15 percent of cases.
The risk factors for melanomas include a family history of melanoma, unusual- looking moles, previous melanoma, immunosuppressive therapy, server, blistering sunburns, many freckles, fair skin and light eyes. People with blond hair or with read hair and blue eyes usually are more likely to get melanoma. Melanoma can sometimes be prevented. By using protection while in the sun like SPF 15 when out side at all times, can help cut the risk in half. Wear a hat and even long sleeves while out in the sun, and even try not to spend a lot of time out in the sun. I work outside in the sun, so I know how hard it is to always remember to put on sunscreen and wear long sleeves living in Florida.
After the doctor performs tests on the patent, a treatment will be planed out. The choices of plans depend on type of tumor, and the stage of the tumor when it is diagnosed. There are also some other factors such as age, health and personal preferences. There are four types of treatment. They are surgery, radiation, chemotherapy, and immunotherapy.
These three types of cancers are only a few of the major types of cancers. Like I said in the beginning of this paper there are over 100 types of cancer. These I personally think are the ones that most people in the world need to know about. I also think that people know about cancers, but not how to prevent them or how to find treatment. If anyone thinks that they might have cancer they should visit their doctor as soon as possible. I have lost and aunt to breast cancer, I have had a great uncle that had lung cancer, and my dad, a family friend and I have had skin cancer. I am sure everyone knows someone that has had some form of cancer. Right now not all cancers can be cured. But I truly believe that someday down the line we will have cures for all forms of cancer.
Cancer Care, Inc.
Brest Cancer Center
Breast Cancer Information Center
Breast Cancer Info.com
OncoLink: Breast Cancer- General Information
AOL Health: Breast Cancer
AOL Keyword: Cancer
AOL Health: Lung Cancer
AOL Keyword: Cancer
The Lung Cancer Information Center
Cancer News on the Net: Lung Cancer Links
American Association for Respiratory Care
American Heart and Lung Institute
National Cancer Institutes/Lung Cancer Biology Page
The New York Times/Women’s Health: Lung Cancer
AOL Health: Skin Cancer
AOL keyword: Cancer
Skin cancer and the Sun
MedicineNet.com- Forum- Skin cancer
NCI Publication- What You Need To Know About Melanoma
Prevention of Skin Cancer
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