Cancer Definition
Cancer is a group of diseases in which cells are hostile, invasive, and sometimes metastatic. These three are considered malignant properties of cancers that differentiate them from benign tumors. Although some benign tumor types are capable of being malignant, they are usually self-limited in their growth and don't invade or metastasize. People from all ages, even fetuses, may be affected with cancer but age is a factor that can raise the risks for more common varieties. About 13% of all deaths are caused by cancer and according to the American Cancer Society, 7.6 million people died from cancer in 2007 across the world. Even plants and animals may be affected by cancer. Abnormalities in the genetic material of the transformed cells practically cause all cancers. Carcinogens such as tobacco smoke, chemicals, radiation or infectious agents may have caused said abnormalities. Some however, may be randomly acquired through errors in DNA replication or inherited. DNA methylation and microRNAs are new aspect of the genetics of cancer pathogenesis that are gaining importance. The tissues from which the cancerous cells originate are used as bases in classifying cancer. There are also two general classes of genes affected by cancer anmely the oncogenes and tumor suppressor genes.
Cancer Diagnosis
Signs or symptoms that appear or found through screening do not lead to definitive diagnosis, which usually require a pathologist's opinion. X-rays, blood tests, CT scans and endoscopy are among the medical tests people with suspected cancers undergo. Performing a biopsy or surgery are procedures where a tissue can be obtained for histological examination. Said examination can identify the type of cell that is spreading as well as its histological grade.
Cancer Treatment
There are several ways of treating cancer such as chemotherapy, surgery, radiation therapy, immunotherapy, monoclonal antibody therapy and other methods. Several experimental cancer treatments are also under works.
Cancer Symptoms and Signs
Cancer symptoms can be divided into three groups: local symptoms, symptoms of metastasis and systemic symptoms. Local symptoms include lumps or swelling, hemorrhage, pain and/or ulceration. Jaundice may also be caused by the compression of surrounding tissues. Enlarged lymph nodes, cough, hemoptysis, hepatomegaly, bone pain, fracture of affected bones and neurological symptoms are among the known symptoms of metastasis. Systemic symptoms meanwhile is comprised of weight loss, fatigue, poor appetite, cacjexia, excessive sweating, specific paraneoplastic phenomena and anemia
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