29-08-2017, 04:34 PM
Hey I'm shesha. I want investigatory project on cancer. Kindly give me.
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download pdf on biology projects for class 12
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Hey I'm shesha. I want investigatory project on cancer. Kindly give me.
30-08-2017, 10:14 AM
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 contaminants. In the developing world, almost 20% of cancers are due to infections such as hepatitis B, hepatitis C, and human papillomavirus infection. These factors act, at least in part, by changing the genes of a cell. Normally, many genetic changes are necessary 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 further investigated by medical imaging and confirmed by biopsy.
Many cancers can be avoided by not smoking, maintaining a healthy weight, not drinking too much alcohol, eating lots of vegetables, fruits and whole grains, getting vaccinated against certain infectious diseases, not eating too much processed and red meat and avoiding too much sunlight. 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. Pain and symptom management are 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 (not including 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. In children, acute lymphoblastic leukemia and brain tumors are the most common, except in Africa, where non-Hodgkin's lymphoma occurs most 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. Financial costs of cancer were estimated at $ 1.16 trillion per year as of 2010.
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