12-05-2017, 01:15 PM
hi am grace i would like to get details on project on the topic of cancer class 12 biology ..My friend linda said project on the topic of cancer class 12 biology will be available here..
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project on the topic of cancer class 12 biology
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hi am grace i would like to get details on project on the topic of cancer class 12 biology ..My friend linda said project on the topic of cancer class 12 biology will be available here..
15-05-2017, 10:49 AM
Cancer
Cancer is a group of diseases that affect abnormal cell growth with the potential to invade or spread to other parts of the body. Not all tumors are cancerous; Benign tumors do not spread to other parts of the body. Possible signs and symptoms include a lump, abnormal bleeding, prolonged coughing, unexplained weight loss and a change in bowel movements. Although these symptoms may indicate cancer, there may be other causes. More than 100 types of cancers affect humans.
Smoking is the cause of about 22% of cancer deaths. Another 10% is due to obesity, poor diet, lack of physical activity and excessive consumption of alcohol. Other factors include certain infections, exposure to ionizing radiation, and environmental pollutants. In the developing world, almost 20% of cancers are due to infections such as hepatitis B, hepatitis C and human papillomavirus (HPV). These factors act, at least in part, by changing the genes of a cell. Many genetic changes are usually required before the cancer develops. Approximately 5-10% of cancers are due to genetic defects inherited from a person's parents. Cancer can be detected by certain signs and symptoms or screening tests. It is then typically further investigated by medical imaging and confirmed by biopsy.
Many cancers can be prevented by not smoking, maintaining a healthy weight, not drinking too much alcohol, eating lots of vegetables, fruits and whole grains, vaccinating against certain infectious diseases, not eating too much processed and red meat and avoiding too much exposure sunlight . Early detection through screening is useful for cervical and colorectal cancer. The benefits of screening for breast cancer are controversial. Cancer is often treated with some combination of radiation, surgery, chemotherapy and targeted therapy. Managing pain and symptoms is an important part of care. Palliative care is particularly important in people with advanced disease. The probability of survival depends on the type of cancer and the extent of the disease at the start of treatment. In children under 15 years of age the diagnosis of the five-year survival rate in the developed world is, on average, 80%. For cancer in the United States the average five-year survival rate is 66%.
By 2015, about 90.5 million people had cancer. About 14.1 million new cases occur annually (excluding skin cancer other than melanoma). It caused about 8.8 million deaths (15.7%) of human deaths. The most common types of cancer in men are lung cancer, prostate cancer, colorectal cancer and stomach cancer. In women, the most common types are breast cancer, colorectal cancer, lung cancer and cervical cancer. If skin cancer other than melanoma was included in the total of new cancers each year, it would account for about 40% of cases. In children, acute lymphoblastic leukemia and brain tumors are more common except in Africa where non-Hodgkin's lymphoma occurs more frequently. In 2012, about 165,000 children under the age of 15 were diagnosed with cancer. The risk of cancer increases significantly with age and many cancers occur more commonly in developed countries. Rates are increasing as more people live to old age and as lifestyle changes occur in the developing world. The financial costs of cancer were estimated at US $ 1.16 billion. Per year as of 2010.
Causes
Most cancers, around 90-95% of cases, are due to environmental factors. The remaining 5-10% is due to inherited genetics. Environmental, as used by cancer researchers, means any cause that is not genetically inherited, such as lifestyle, economic and behavioral factors and not simply contamination. Common environmental factors that contribute to cancer death are tobacco (25-30%), diet and obesity (30-35%), infections (15-20%), radiation (both ionizing and non-ionizing , Up to 10%), Stress, lack of physical activity and environmental contaminants.
In general it is not possible to prove what caused a particular cancer because the various causes do not have specific fingerprints. For example, if a person who uses tobacco largely develops lung cancer, then it was probably caused by tobacco use, but since everyone has a small chance of developing lung cancer as a result of pollution or radiation, the Cancer may have developed for one of those reasons. With the exception of rare transmissions that occur with pregnancies and occasional organ donors, cancer is generally not a communicable disease.
Prevention
Cancer prevention is defined as active measures to decrease the risk of cancer. The vast majority of cancer cases are due to environmental risk factors. Many of these environmental factors are manageable lifestyle choices. Therefore, cancer is generally preventable. Between 70% and 90% of common cancers are due to environmental factors and therefore potentially preventable.
More than 30% of cancer deaths could be avoided by avoiding risk factors such as smoking, excess weight and obesity, insufficient diet, physical inactivity, alcohol, sexually transmitted infections and air pollution. Not all environmental causes are controllable, such as natural background radiation and cancers caused by hereditary genetic disorders and, therefore, can not be prevented by personal behavior.
Cancer begins in your cells, which are the building blocks of your body. Normally, your body forms new cells when it needs them, replacing old cells that die. Sometimes this process goes awry. New cells grow even when they do not need them, and old cells do not die when they should. These additional cells can form a mass called a tumor. Tumors can be benign or malignant. Benign tumors are not cancer, while malignant tumors are. Malignant tumor cells can invade nearby tissues. They can also rupture and spread to other parts of the body.
Cancer is not just one disease but many diseases. There are more than 100 different types of cancer. Most cancers are named for where they begin. For example, lung cancer begins in the lung, and breast cancer begins in the chest. The spread of cancer from one part of the body to another is called metastasis. Symptoms and treatment depend on the type of cancer and how advanced it is. Most treatment plans can include surgery, radiation and / or chemotherapy. Some may include hormone therapy, immunotherapy or other types of biological therapy or stem cell transplantation.
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