Colorectal Cancer Defined : Latest Research

by National Institute on Aging

(Page 5 of 5)

Researchers continue to look at new ways to treat, diagnose, and prevent colorectal cancer. Many are testing other types of treatments in clinical trials.

Various drugs are under study as possible treatments for colorectal cancer. In May 2002, researchers found that a drug regimen consisting of oxaliplatin, 5-fluorouracil, and leucovorin can improve outcomes for patients with colorectal cancer.

A 2005 study found that patients who took the drug Avastin™ with their standard chemotherapy treatment had a longer survival than those who did not take Avastin. The generic name for Avastin is bevacizumab.

Scientists are also working on new vaccines and monoclonal antibodies that may improve how patients' immune systems respond to colorectal cancers. Monoclonal antibodies are a single type of antibody that researchers make in large amounts in a laboratory.

New surgical techniques have reduced the number of patients needing a permanent colostomy. A colostomy is an opening made in the abdomen for waste to pass out of the body before it reaches the rectum. In many cases, the surgeon can reconnect the healthy parts of the colon back together after removing the cancer. This way, the colon can function just as it did before.

Scientists are looking at the role that sigmoidoscopy and colonoscopy may play in detecting early stage disease and reducing deaths from colorectal cancer.

Two studies reported in the July 20, 2000 issue of New England Journal of Medicine showed that colonoscopy can find many pre-cancerous polyps that sigmoidoscopy misses. However, more studies are needed to find out if colonoscopy can actually reduce the number of deaths from colorectal cancer.

The National Cancer Institute's Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, or PLCO Trial, will provide important information about the role of sigmoidoscopy and colonoscopy in reducing deaths from colon and rectal cancers.

The PLCO trial, involving 148,000 volunteers aged 55 to 74, is comparing two groups of people over a 10-year period to see if the group that receives sigmoidoscopies has fewer deaths from colorectal cancer.

Researchers have developed a test called virtual colonoscopy. This test would let doctors view the entire colon using 3-D computer graphics from a computerized tomography scan, or CT scan. This technology could reduce the need for sigmoidoscopies and colonoscopies, which are more invasive. So far, however, virtual colonoscopy has not proven to be a better method of detection.

Preventing colorectal cancer is a concern of many researchers. Many continue to pursue leads on how certain foods may lead to colorectal cancer and how other foods may help to prevent it.

Scientists are also doing research on chemoprevention - the use of drugs to prevent cancer from developing in the first place. For example, researchers found that certain anti-inflammatory drugs helped keep intestinal tumors from forming in rats. These drugs have also been evaluated in people, but several studies noting serious side effects have caused the research to proceed at a slower pace.

Studies have shown that non-steroidal anti-inflammatory drugs can keep large-bowel polyps from forming. Bowel polyps can start out benign, or non-cancerous, but can become cancerous.

Genes involved in colorectal cancer continue to be identified and understood. Hereditary nonpolyposis colorectal cancer, or HNPCC, is one condition that causes people in a certain family to develop colorectal cancer at a young age. The discovery of four genes involved with this disease has provided crucial clues about the role of DNA repair in colorectal and other cancers.

Scientists are continuing to identify genes associated with colon cancers that run in families. Using traditional screening methods on people from families that carry these genes may be another way to identify cancers at an early stage and cut deaths from colorectal cancer. Genetic screening of people at high risk may become more common in the near future.

About the Author

www.nia.nih.gov
NIA, one of the 27 Institutes and Centers of NIH, leads a broad scientific effort to understand the nature of aging and to extend the healthy, active years of life. In 1974, Congress granted authority to form NIA to provide leadership in aging research, training, health information dissemination, and other programs relevant to aging and older people.