Colorectal Cancer Glossary of Terms
Laser surgery: destruction of tissue using a small, powerful, highly focused beam of light.
Laxative: medications that increase the action of the intestines or stimulate the addition of water to the stool to increase its bulk and ease its passage. Laxatives commonly are prescribed to treat constipation.
Local therapy: treatment that is directed at cells in the tumor and the area close to it.
Localized cancer: cancer that hasn't spread to other parts of the body.
Lymph: clear fluid that travels through the lymphatic system and carries cells that help fight infection and disease.
Lymphatic system: circulatory system that includes an extensive network of lymph vessels and lymph nodes. The lymphatic system helps coordinate the immune system's function to protect the body from foreign substances.
MRI: a test that produces images of the body without the use of X-rays. MRI uses a large magnet, radio waves, and a computer to produce these images.
Malignant: cancerous; can spread to other parts of the body.
Mesentery: membranous tissue that carries blood vessels and lymph glands, and attaches various organs to the inner wall of the abdomen.
Metastasize: to spread from one part of the body to another. When cancer cells metastasize and cause secondary tumors, the cells in the secondary tumor are like those in the original cancer.
Microsatellite instability: mistakes in DNA. Microsatellite instability is where the length of small sequences of DNA differs between tumor cells and normal cells; their appearance is a clue to the presence of abnormal DNA repair. The presence of microsatellite instability conveys resistance to fluoropyrimidine chemotherapy (5-FU or capecitabine).
Mismatch repair genes: genes responsible for correcting errors in DNA when cells divide. In hereditary non-polyposis colorectal cancer (HNPCC), recent research has discovered mutations in a variety of genes that are thought to be a part of the DNA mismatch repair system, therefore predisposing families with HNPCC to the development of cancer.
Mismatch repair: DNA constantly has to produce new strands of itself. When this is done incorrectly, there are special genes involved in correcting the mistake. If this is not done, or not done properly, a tumor can grow in the place of normal cells.