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.
Unfortunately, colon cancers can be well advanced before they are detected. The
most effective prevention of colon cancer is early detection and removal of
precancerous colon polyps before they turn cancerous. Even in cases where cancer
has already developed, early detection still significantly improves the chances
of a cure by surgically removing the cancer before the disease spreads to other
organs. Multiple world health organizations have suggested general screening
guidelines.
Digital rectal examination and stool occult blood testing
It is recommended that all individuals over the age of 40 have yearly digital
examinations of the rectum and their stool tested for hidden or "occult" blood.
During digital examination of the rectum, the doctor inserts a gloved finger
into the rectum to feel for abnormal growths. Stool samples can be obtained to
test for occult blood (see below). The prostate gland can be examined at the
same time.
An important screening test for colorectal cancers and polyps is the stool
occult blood test. Tumors of the colon and rectum tend to bleed slowly into the
stool. The small amount of blood mixed into the stool is usually not visible to
the naked eye. The commonly used stool occult blood tests rely on chemical color
conversions to detect microscopic amounts of blood. These tests are both
convenient and inexpensive. A small amount of stool sample is smeared on a
special card for occult blood testing. Usually, three consecutive stool cards
are collected. A person who tests positive for stool occult blood has a 30%
to 45% chance of having a colon polyp and a 3% to 5% chance of having a colon cancer. Colon cancers found under these
circumstances tend to be early and have a better long-term prognosis.
It is important to remember that having stool tested positive for occult blood
does not necessarily mean the person has colon cancer. Many other conditions can
cause occult blood in the stool. However, patients with a positive stool occult
blood should undergo further evaluations involving barium enema x-rays,
colonoscopies, and other tests to exclude colon cancer, and to explain the
source of the bleeding. It is also important to realize that stool which has
tested negative for occult blood does not mean the absence of colorectal cancer
or polyps. Even under ideal testing conditions, at least 20% of colon
cancers can be missed by stool occult blood screening. Many patients with colon
polyps are tested negative for stool occult blood. In patients suspected of
having colon tumors, and in those with high risk factors for developing
colorectal polyps and cancer, flexible sigmoidoscopies or screening
colonoscopies are performed even if the stool occult blood tests are negative.
Flexible sigmoidoscopy and
colonoscopy
Beginning at age 50, a flexible sigmoidoscopy screening tests is
recommended every three to five years. Flexible sigmoidoscopy is an exam of the rectum
and the lower colon using a viewing tube (a short version of colonoscopy).
Recent studies have shown that the use of screening flexible sigmoidoscopy can
reduce mortality from colon cancer. This is a result of the detection of polyps
or early cancers in people with no symptoms. If a polyp or cancer is found, a
complete colonoscopy
is recommended. The majority of colon polyps can be
completely removed by colonoscopy without open surgery. Recently doctors are
recommending screening colonoscopies instead of screening flexible
sigmoidoscopies for healthy individuals starting at ages 50-55. Please read the
Colon Cancer Screening article.
Patients with a high risk of developing colorectal cancer may undergo
colonoscopies starting at earlier ages than 50. For example, patients with
family history of colon cancer are recommended to start screening colonoscopies
at an age 10 years before the earliest colon caner diagnosed in a first-degree
relative, or five years earlier than the earliest precancerous colon polyp
discovered in a first-degree relative. Patients with hereditary colon cancer
syndromes such as FAP, AFAP, HNPCC, and MYH are recommended to begin
colonoscopies early. The recommendations differ depending on the genetic defect,
for example in FAP; colonoscopies may begin during teenage years to look for the
development of colon polyps. Patients with a prior history of polyps or colon
cancer may also undergo colonoscopies to exclude recurrence. Patients with a
long history (greater than 10 years) of chronic ulcerative colitis have an
increased risk of colon cancer, and should have regular colonoscopies to look
for precancerous changes in the colon lining.
Genetic counseling and testing
Blood tests are now available to test for FAP, AFAP, MYH, and HNPCC hereditary
colon cancer syndromes. Families with multiple members having colon cancers,
members with multiple colon polyps, members having cancers at young ages, and
having other cancers such as cancers of the ureters, uterus, duodenum, etc.,
should be referred for genetic counseling followed possibly by genetic testing.
Genetic testing without prior counseling is discouraged because of the extensive
family education that is involved and the complicated nature of interpreting the
test results.
The advantages of genetic counseling followed by genetic testing include: (1)
identifying family members at high risk of developing colon cancer to begin
colonoscopies early; (2) identifying high risk members so that screening may
begin to prevent other cancers such as ultrasound tests for uterine cancer,
urine examinations for ureter cancer, and upper endoscopies for stomach and
duodenal cancers; and (3) alleviating concern for members who test negative for the
hereditary genetic defects.
Diet and colon cancer to prevent colon cancer
People can change their eating habits by reducing fat intake and increasing
fiber (roughage) in their diet. Major
sources of fat are meat, eggs, dairy products, salad dressings, and oils used in
cooking. Fiber is the insoluble, nondigestible part of plant material present
in fruits, vegetables, and whole-grain breads and cereals. It is postulated that
high fiber in the diet leads to the creation of bulky stools which can rid the
intestines of potential carcinogens. In addition, fiber leads to the more rapid
transit of fecal material through the intestine, thus allowing less time for a
potential carcinogen to react with the intestinal lining. For additional
information, please read the Colon Cancer
Prevention article.
Abdominal pain is pain in the belly and can be acute or chronic. Causes include inflammation, distention of an organ, and loss of the blood supply to an organ. Abdominal pain can reflect a major problem with one of the organs in the abdomen such as the appendix, gallbladder, large and small intestine, pancreas, liver, colon, duodenum, and spleen.
Rectal bleeding (hematochezia) refers to the passage of bright red blood from the anus. Rectal bleeding may be moderate to severe and most bleeding comes from the colon, rectum, or anus. Common causes include anal fissures, hemorrhoids, diverticulitis, and more.
Constipation is defined medically as fewer than three stools per week and severe constipation as less than one stool per week. Constipation usually is caused by the slow movement of stool through the colon. There are many causes of constipation including medications, poor bowel habits, low fiber diets, abuse of laxatives, hormonal disorders, and diseases primarily of other parts of the body that also affect the colon.
Lymph nodes help the body's immune system fight infections. Causes of swollen lymph nodes (glands) may include infection (viral, bacterial, fungal, parasites). Symptoms of swollen lymph nodes vary greatly. They can sometimes be tender, painful or disfiguring. The treatment of swollen lymph nodes depends upon the cause.
Though uterine cancer's cause is unknown, there are many factors that will put a woman at risk, including: over age 50, endometrial hyperplasia, using hormone replacement therapy, obesity, using tamoxifen, being Caucasian, having colorectal cancer. Symptoms of cancer of the uterus (endometrial cancer) include abnormal vaginal bleeding, painful urination, painful intercourse, and pelvic pain. Treatment depends on staging and may include radiation therapy or hormone therapy.
Ulcerative colitis is a chronic inflammation of the colon. Symptoms include abdominal pain, diarrhea, and rectal bleeding. Ulcerative colitis is closely related to Crohn's disease, and together they are referred to as inflammatory bowel disease. Treatment depends upon the type of ulcerative colitis diagnosed.
Ascites, the accumulation of fluid in the abdominal cavity is most commonly caused by cirrhosis of the liver. Some of the other causes of ascites include portal hypertension, congestive heart failure, blood clots, and pancreatitis. The most common symptoms include increased abdominal girth and size, abdominal bloating, and abdominal pain. Treatment depends on the cause of ascites.
Inflammation of the inner lining of the colon is referred to as colitis. Symptoms of the inflammation of the colon lining include diarrhea, pain, and blood in the stool. There are several causes of colitis including infection, ischemia of the colon, inflammatory bowel disease (Crohn's disease, Ulcerative colitis, or microscopic colitis). Treatment depends on the cause of the colitis.
Cancer is a disease caused by an abnormal growth of cells, also called malignancy. It is a group of 100 different diseases, and is not contagious. Cancer can be treated through chemotherapy, a treatment of drugs that destroy cancer cells.
A colon polyp is a benign tumor of the large intestine. Benign polyps do not invade nearby tissue or spread to other parts of the body. Benign polyps can easily be removed during colonoscopy and are not life threatening. If benign polyps are not removed from the large intestine, they can become malignant over time.
Anal cancer, cancer located at the end of the large intestine, has symptoms that include anal or rectal bleeding, anal pain or pressure, anal discharge or itching, a change in bowel movements, and/or a lump in the anal region. Treatment for anal cancer may involve radiation, chemotherapy, or surgery and depends upon the stage of the cancer, its location, whether cancer is eradicated after the first treatment, and whether the patient has HIV.
Though it's difficult to say why some people develop cancer while others don't, research shows that certain risk factors increase a person's odds of developing cancer. These risk factors include growing older, family history of cancer, diet, alcohol and tobacco use, and exposure to sunlight, ionizing radiation, certain chemicals, and some viruses and bacteria.
Digestion is the complex process of turning food you eat into the energy you need to survive. The digestive process also involves creating waste to be eliminated, and is made of a series of muscles that coordinate the movement of food.
Gardners' syndrome, or familial adenomatous polyposis (FAP), is an inherited condition in which cancer of the colon and rectum develop. Colon polyps and growths may develop as early as the teens. If these polyps are not removed, they will become cancerous. There are different inheritance patterns for familial adenomatous polyposis.
Most often, caregivers take care of other adults who are ill or disabled. Less often, caregivers are grandparents raising their grandchildren. The majority of caregivers are middle-aged women. Caregiving can be very stressful, so it's important to recognize when it's putting to much strain on you and to take steps to prevent/relieve stress.
Disease prevention in men includes routine screening tests that are part of basic prevention medicine. Take an active role in your own health care and discuss screening tests with your doctor early in life. Age of screening and timing of screening depends upon the condition being assessed.
Disease prevention in women includes screening tests that are a basic part of prevention medicine. All screening tests
are commonly available through your general doctor. Some specialized tests may be available elsewhere.
Endometrial cancer, or uterine cancer, affects the endometrium of the uterus. It's the most common invasive cancer of the female reproductive system. Risk factors include smoking, obesity, lack of exercise, taking estrogen-only hormone therapy, early menstruation, late menopause, and never being pregnant.
Your health care provider may refer you to a genetic professional. Universities and medical centers also often have affiliated genetic professionals, or can provide referrals to a genetic professional or genetics clinic. Genetic counseling provides patients and family members the tools to make the right choice in regard to test for a disease or condition.
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