Home >> HealthCenter >> Condition

Please enter your email:

Cancer

Cancer

Cancer is a group of diseases in which cells are aggressive (grow and divide without respect to normal limits), invasive (invade and destroy adjacent tissues), and/or metastatic (spread to other locations in the body). These three malignant properties of cancers differentiate them from benign tumors, which are self-limited in their growth and do not invade or metastasize (although some benign tumor types are capable of becoming malignant). Cancer may affect people at all ages, even fetuses, but risk for the more common varieties tends to increase with age.[1] Cancer causes about 13% of all deaths.[2] Apart from people, forms of cancer may affect animals and plants.

Nearly all cancers are caused by abnormalities in the genetic material of the transformed cells. These abnormalities may be due to the effects of carcinogens, such as tobacco smoke, radiation, chemicals, or infectious agents. Other cancer-promoting genetic abnormalities may be randomly acquired through errors in DNA replication, or are inherited, and thus present in all cells from birth. Complex interactions between carcinogens and the host genome may explain why only some develop cancer after exposure to a known carcinogen. New aspects of the genetics of cancer pathogenesis, such as DNA methylation, and microRNAs are increasingly being recognized as important.

Genetic abnormalities found in cancer typically affect two general classes of genes. Cancer-promoting oncogenes are often activated in cancer cells, giving those cells new properties, such as hyperactive growth and division, protection against programmed cell death, loss of respect for normal tissue boundaries, and the ability to become established in diverse tissue environments. Tumor suppressor genes are often inactivated in cancer cells, resulting in the loss of normal functions in those cells, such as accurate DNA replication, control over the cell cycle, orientation and adhesion within tissues, and interaction with protective cells of the immune system.

12345
Next Last References

Home   |   About Us   |   Contact Us   |   Privacy   |   Terms Of Use   |   Advertise With Us   |   Sitemap
Copyright © 2017 Responsive Health
This site is intended to provide you with health information from publicly available sources, supporting vendors and partnered sources. While We make every effort to ensure that the information on this site is accurate, We make absolutely no assumption, inference, or declaration stating the information provided should be use as a source influencing any decisions on medical, diagnosis or treatment, or advice about what providers to use. The Site is an informational resource used for educational purposes only and cannot be used as a source used to make changes to medical treatment or lifestyle decisions without first consulting with your physician.