How Cancer Develops
posted by Oncology Team | October 4, 2016
One out of every two men will develop cancer at some time in life, according to the American Cancer Society, and one out of three women will develop the disease. Cancer claims more than a half a million lives each year, according to the Centers for Disease Control and Prevention (CDC), making it the second leading cause of death in the United States.
Normal cells divide in an orderly way, creating just enough new cells to replace dying cells that are worn out or damaged. Cancer starts when abnormal cells begin to grow out of control and crowd out normal cells, which makes it hard for organs and tissues to work properly.
It can start any place in the body and some types of cancer can spread. Cancer can start in the bones, lungs, breast, prostate or even in the blood. In a process known as metastasis, cancer can spread to nearby or faraway organs.
Cancer is not a single disease – there are more than 100 different types of cancer. While these types of cancer are similar in some ways, they are quite different in others.
Cancer can be benign, meaning it will stay localized in one spot. It can also be malignant, meaning the cancer can metastasize. Many types of cancer cause the formation of tumors, which are areas featuring an abnormal proliferation of cells. Some cancers, like leukemia and lymphoma, do not cause solid tumors.
Doctors classify tumors according to the type of cell from which the cancer started. There are three main groups of tumors: carcinomas, sarcomas, and leukemias or lymphomas. About 90 percent of cancer cases in humans are carcinomas, which are cancers that develop in the epithelial cells of the skin and tissues covering the organs of the body. Sarcomas, rare in humans, are solid tumors that start in connective tissue, such as muscle, bone and cartilage. Leukemias start in blood-forming cells and lymphomas start in cells of the immune system.
At the cellular level, the development of cancer involves mutation and selection of cells capable of quick replication, survival, invasion of healthy tissue and metastasis. A genetic alteration, often caused by a lifestyle choice, leads to the fast reproduction of a single abnormal cell. Rapid proliferation of cancer cells then crowds out healthy cells. The tumor grows as more mutations occur within its cells.
Cancer incidence is highest in Maine, Massachusetts, New York, Pennsylvania, West Virginia, Kentucky, Mississippi and Louisiana, according to the CDC, and lowest in Oregon, Idaho, California, Wyoming, Utah, Colorado, Arizona, New Mexico, Texas, Florida, Alaska and Hawaii.
The incidence rates of breast cancer are highest in the Northeast, according to the CDC, followed by the Midwest and the South. The South leads the nation in lung cancer cases in men, followed by the Midwest and the Northeast. The incidence of lung cancer in women is highest in the Midwest. Such geographical differences are evident in colorectal, prostate and other types of cancer.
Several factors may play a role in the development of cancer, including demographic factors such as ethnicity, socioeconomic status and age. Diet, smoking, alcohol use, physical activity and other lifestyle choices also play a role, as does the age of first menses and pregnancy in women. Sun exposure can affect cancer incidence rates. Occupational and environmental exposures to chemicals or radiation also can increase the risk for cancer. Availability and use of cancer screenings and early diagnosis affects cancer rates. Residents of some areas may have more access to advanced medical care and appropriate health care management.
While genetics can influence your risk for cancer, you can reduce your risk for developing the disease. Get regular cancer screenings that gives you and your doctor to treat cancer in its earliest stages, when it is most responsive to treatments. Achieve and maintain a healthy weight; obesity is strongly associated with the development of cancer. Exercise regularly and eat a healthy diet. Avoid tobacco and limit alcohol.
For more information on how cancer develops and to learn more ways you can reduce your risk for the disease, talk to our cancer care specialists at Revere Health.
This information is not intended to replace the advice of a medical professional. You should always consult your doctor before making decisions about your health.