Cancer

Cancer



Cancer

1. Introduction

Cancer is not just one disease, but a large group of almost one hundred diseases. Its two main characteristics are uncontrolled growth of the cells in the human body and the ability of these cells to migrate from the original site and spread to distant sites. If the spread is not controlled, cancer can result in death.

2. Global epidemic of cancer

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. (Hilleman,,2006,6)

Cancer can attack anyone. Since the occurrence 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 (in women), and prostate cancer (in men). In addition, cancer of the kidneys, ovaries, uterus, pancreas, bladder, rectum, and blood and lymph node cancer (leukemias and lymphomas) are also included among the 12 major cancers that affect most Americans.(Bystryn,2007,190)

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.(Chen,2009,795)

There are some cancers that have a genetic basis. In other words, an individual could inherit faulty DNA from his parents, which could predispose him to getting cancer. While there is scientific evidence that both factors (environmental and genetic) play a role, less than 10% of all cancers are purely hereditary. (Herlyn,2004,65)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. (Houghton,2002,1384) 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.

3. Prevalence Of Cancer

Cancer is, in general, more common in industrialized nations, but there has been a growth in cancer rates in developing countries, particularly as these nations adopt the diet and lifestyle habits of industrialized countries. Over one million people in the United States get cancer each year. Anyone can get cancer at any age; however, about 80 percent of all cancers occur in people over the age of fifty-five. Cancer can affect any site in the body. About one hundred human cancers are recognized. The four most common cancers in the United States are: lung, colon/rectum, breast, and prostate. (Herlyn,2004,65)Together, these cancers account for over 50 percent of total cancer cases in the United States each year.

There is a marked variation among countries in incidence of different ...