Dr. Lee was born in Shanghai, China, and received his college and medical training in the United States. He is fluent in English and three Chinese dialects. He graduated with chemistry departmental honors from Harvey Mudd College. He was appointed president of AOA society at UCLA School of Medicine. He underwent internal medicine residency and gastroenterology fellowship training at Cedars Sinai Medical Center.
Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.
Cancer of the colon and the rectum
(also known as colon cancer or colo-rectal cancer)
is a malignant growth arising from the
inner lining of the colon or rectum. Colo-rectal cancer is a major cause of cancer-related deaths among men and women in the
The good news is that colo-rectal cancer is both curable and preventable if
it is detected early and completely removed before the cancerous cells
metastasize (spread) to other parts of the
body. Colo-rectal cancer can be prevented by removing colo-rectal
polyps before they grow and change into cancers, or by using natural
substances or man-made chemicals to prevent the colo-rectal polyps from changing
into cancer. (Using natural substances or chemicals to prevent cancer is called
Measures to prevent diseases usually fall into one of five categories of safety and
effectiveness. These categories are:
Measures that have scientifically-proven effectiveness
and long-term safety
Measures that probably are effective but may have
long-term, adverse side effects
Measures that probably are effective, and safe
Measures that have been found to be ineffective
Measures that have no scientific basis and no
studies to measure effectiveness and safety
Colonoscopy and flexible sigmoidoscopy (along with
digital rectal examination and stool occult blood testing) are the
primary and most important tools for both
preventing colo-rectal cancers and detecting early colo-rectal cancers.
colo-rectal cancers arise from colo-rectal polyps (small growths on the inner
lining of the colon and the rectum). Even though colo-rectal polyps are
initially benign, they can grow and change into colo-rectal cancers over a
period of time ranging from five to twenty years. A large study that was
conducted in several research centers in the United States showed that patients
who had their polyps removed (usually via colonoscopy)
had a 90% decrease in colo-rectal cancer.
Screening recommendations for individuals with average risk of colon cancer
The life-time risk for an adult American to develop colorectal cancer is approximately 6%. Fecal occult blood tests and flexible sigmoidoscopic examinations are the recommended screening tests for these individuals at average risk for developing colorectal cancer.