Defination

Cancer Defination:
Cancer is not just one infection but a outsized crowd of exactly one hundred diseases. Its two main personality are hysterical growth of the cells in the creature body and the faculty of these cells to voyage from the novel site and spread to far-flung sites. If the distend is not controlled, disease can product in death.
Progression of events :
One out of every four deaths in the United States is from cancer. It is second only to heart disease as a cause of death in the states. About 1.2 million Americans are diagnosed with cancer annually; more than 500,000 die of cancer annually.
Cancer can attack anyone. Since the happening of cancer increases as individuals’ age, most of the cases are seen in adults, middle-aged or older. Sixty percent of all cancers are diagnosed in people who are older than 65 years of age. The most common cancers are skin cancer, lung cancer, colon cancer, breast cancer, and prostate cancer (in men). In addition, cancer of the kidneys, ovaries, uterus, pancreas, bladder, rectum, and blood and lymph node cancer (leukemia’s and lymphomas) are also included among the 12 major cancers that affect most Americans.
Cancer, by definition, is a disease of the genes. A gene is a small part of DNA, which is the master molecule of the cell. Genes make "proteins," which are the ultimate workhorses of the cells. It is these proteins that allow our bodies to carry out all the many processes that permit us to breathe, think, move, etc.
Throughout people's lives, the cells in their bodies are budding dividing, and replace themselves. Many genes produce proteins that are involved in controlling the processes of cell growth and division. An alteration to the DNA molecule can disrupt the genes and produce faulty proteins. This causes the cell to become abnormal and lose its restraints on growth. The abnormal cell begins to divide uncontrollably and eventually forms a new growth known as a "lump or neoplasm In a healthy individual, the immune system can recognize the neoclassic cells and destroy them before they get a chance to divide.
Tumors are of two types, benign or malignant. A benign tumor is not considered cancer. It is slow growing, does not spread or invade surrounding tissue, and once it is removed, it doesn't usually recur. A malignant tumor, on the other hand, is cancer. It invades surrounding tissue and spreads to other parts of the body. If the cancer cells have spread to the surrounding tissues, then, even after the malignant tumor is removed, it generally recurs.
A majority of cancers are caused by changes in the cell's DNA because of damage due to the environment. Environmental factors that are responsible for causing the initial mutation in the DNA are called carcinogens, and there are many types.
There are some cancers that have a heritable basis. In other words, an personage could inherit faulty DNA from his parents, which could predispose him to getting cancer. While there is scientific evidence that both factors play a role, less than 10% of all cancers are purely hereditary. Cancers that are known to have a hereditary link are breast cancer, colon cancer, ovarian cancer, and uterine cancer. Besides genes, certain physiological traits could be inherited and could contribute to cancers. For example, inheriting fair skin makes a person more likely to develop skin cancer, but only if they also have prolonged exposure to intensive sunlight.