COLORECTAL CANCER

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COLORECTAL CANCER
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Introduction

• Together, cancers of the colon and rectum are
  among the most common cancers in the united
  states. They are second only to lung cancer as
  the leading cause of cancer-related deaths in the
  United States.
• In 1997, 131,000 Americans were diagnosed and
  55,000 died from colorectal cancer.

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Introduction - continued

• Without screening or taking preventive action,
  one in 17 persons will develop colorectal cancer.
• They occur in both men and women and are most
  often found among people who are over the age of
  50.

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What Is Cancer?

• Normal cell processes.
• Cells grow, divide and grow more cells to provide
  proper health and function.
• Tumors are an abnormal process where the cells
  keep growing, even when new cells are not needed.
• These Tumor growths can be benign or malignant.

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Tumors

• Benign Tumors- These are not cancer and can
  usually be removed and do not threaten life. A
  polyp is a benign tumor.
• Malignant Tumors- These are cancer! The cells
  are abnormal and divide uncontrollably. They
  invade surrounding tissue and can metastasize to
  other areas.

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Benign and Malignant tumors

• Benign bilobed tubular adenoma
• this is a benign polyp
• This is a malignant polyp
• APPEARANCE CAN BE
• DECIEVING.

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Colorectal Cancer Who's at Risk?

• Age
• Diet
• Polyps
• Personal Medical History
• Family Medical History
• Ulcerative Colitis

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RISK FACTORS for Colon Cancer

• Age.
• Colorectal cancer is more likely to occur as
  people get older. This disease is more common in
  people over the age of 50. However, colorectal
  cancer can occur at younger ages, even, in rare
  cases, in the teens.

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RISK FACTORS for Colon Cancer - Continued

• Diet.
• Colorectal cancer seems to be associated with
  diets that are high in fat and calories and low
  in fiber. Researchers are exploring how these and
  other dietary factors play a role in the
  development of colorectal cancer.

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RISK FACTORS for Colon Cancer - Continued

• Polyps.
• Polyps are benign growths on the inner wall of
  the colon and rectum. They are fairly common in
  people over age 50. Some types of polyps increase
  a person's risk of developing colorectal cancer.
• A polyp is a benign tumor. It is extra tissue
  that grows on the lining of the colon or rectum.
  These polyps should be removed because they can
  become malignant.

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RISK FACTORS for Colon Cancer - Continued

• Personal Medical History.
• Research shows that women with a history of
  cancer of the ovary, uterus, or breast have a
  somewhat increased chance of developing
  colorectal cancer. Also, a person who has already
  had colorectal cancer may develop this disease a
  second time.

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RISK FACTORS for Colon Cancer - Continued

• Family Medical History.
• First-degree relatives (parents, siblings,
  children) of a person who has had colorectal
  cancer are somewhat more likely to develop this
  type of cancer themselves, especially if the
  relative had the cancer at a young age. If many
  family members have had colorectal cancer, the
  chances increase even more.

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RISK FACTORS for Colon Cancer - Continued

• Ulcerative Colitis.
• a condition in which the lining of the colon
  becomes inflamed. Having this condition
  increases a person's chance of developing
  colorectal cancer, especially the longer they
  have the condition.

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Colorectal Cancer Reducing the Risk

• Research shows that colorectal cancer develops
  gradually from benign polyps. Early detection and
  removal of polyps may help to prevent colorectal
  cancer.

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Colorectal Cancer Reducing the Risk

• Studies are looking at smoking cessation, use of
  dietary supplements, use of aspirin or similar
  medicines, decreased alcohol consumption, and
  increased physical activity to see if these
  approaches can prevent colorectal cancer.

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Colorectal Cancer Reducing the Risk - Continued

• Some studies suggest that a diet low in fat and
  calories and high in fiber can help prevent
  colorectal cancer.

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Colorectal Cancer Reducing the Risk - Continued

• Researchers have discovered that changes in
  certain genes (basic units of heredity) raise the
  risk of colorectal cancer. Individuals in
  families with several cases of colorectal cancer
  may find it helpful to talk with a genetic
  counselor.
• The genetic counselor can discuss the
  availability of a special blood test to check for
  a genetic change that may increase the chance of
  developing colorectal cancer. Although having
  such a genetic change does not mean that a person
  is sure to develop colorectal cancer.

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Detecting Cancer Early

• Screening for Colorectal Cancer
• When should you start?

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Colorectal Cancer Screening Tests

• Fecal Occult Blood Tests
• Sigmoidoscopy
• Colonoscopy
• Double Contrast Barium Enema

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Fecal Occult Blood Tests

• (FOBT) is a test used to check for hidden blood
  in the stool. Sometimes cancers or polyps can
  bleed, and FOBT is used to detect small amounts
  of bleeding.
• Special cards are coated with a stool sample and
  returned to the lab. This test examines a
  patient's solid waste (stool) for occult (hidden)
  blood. Studies show that a fecal occult blood
  test performed every 1 or 2 years in people
  between the ages of 50-80 years decreases the
  number of deaths due to colorectal cancer by 15
  to 25.

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Fecal Occult Blood Tests

• The peroxidase-like activity of the hemoglobin
  causes the phenolic oxidation of the guaiac
  impregnated paper to an easily recognizable blue
  compound (JAMA). In various screening programs,
  between 2 and 6 of tests are found to be
  positive. Within the positive group, carcinomas
  have been uncovered in 5-10 of the screened
  group and adenomas have been identified in 20-40
  (Fleischer).

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Fecal Occult Blood Tests

• Although FOBT is an imperfect way to detect
  colorectal cancers and adenomas, no other more
  cost-effective and generally acceptable
  alternative has been identified. At present the
  American Cancer Society and American College of
  Physicians still recommend testing individuals
  aged 50 and older without risk factors and
  individuals aged 40 and older with identifiable
  risk factors.

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Sigmoidoscopy

• A sigmoidoscopy is an examination of the rectum
  and lower colon (sigmoid colon) using a lighted
  fiber optic instrument called a sigmoidoscope.
• Lower bowel must be prepped.
• Looks at only the lower 60 cm.
• Done without anesthesia.

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Sigmoidoscopy

• Using the new 60 cm sigmoidoscope approximately
  55 of de novo adenomas and adenocarcinomas can
  be identified with 85 sensitivity (Eddy).
• At the current time the American College of
  Physicians recommends the test every 3-5 years
  beginning at age 50. This recommendation is
  supported by the American Cancer Society, The
  National Cancer Institute, and the American
  College of Gynecologists.

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Colonoscopy

• A Colonoscopy is an examination of the rectum and
  entire colon using a lighted fiber optic
  instrument called a colonoscope.
• Bowel must be prepped.
• Done under IV sedation anesthesia.
• The end result of any other positive screening
  test!!!

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Double Contrast Barium Enema

• is a series of x-rays of the colon and rectum.
  The patient is given an enema with a solution
  that contains barium, which outlines the colon
  and rectum on the x-rays.
• Bowel must be prepped.
• Done without anesthesia.
• Barium enema is relatively insensitive for small
  polyps.

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Recognizing Symptoms of Colorectal Cancer

• Common signs and symptoms of colorectal cancer
  include
• Change in Bowel Habits.
• Diarrhea, constipation or a feeling of not
  emptying.
• Blood in the stool.
• Weight loss for no reason.
• Constant tiredness.
• General abdominal discomfort including gas pains,
  bloating, fullness and/or cramps.
• Vomiting.

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Diagnosing Colorectal Cancer

• To help find the cause of symptoms, the doctor
  evaluates a person's medical history. The doctor
  also performs a physical exam and may order one
  or more diagnostic tests.
• Diagnostic tests include the screening exams
  discussed before.

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Why Should I Have a Screening Test?

• Most patients (65) present with advanced
  disease.
• The 5-year case-fatality rate is 50.
• For localized disease, the 5-year survival rate
  approaches 90 for cancer of the colon and 80
  for cancer of the rectum.

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Why Should I Have a Screening Test?

• In general, on initial (prevalence) examinations,
  from 1 to 5 of unselected persons tested with
  FOBT have positive test results. Of those with
  positive test results, approximately 2 to 10
  have cancer and approximately 20 to 30 have
  adenomas, depending on how the test is done.

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Findings on Colonoscopy

• Normal transverse colon.
• Note the triangle shaped walls
• characteristic of this area of the colon.
• Normal Cecum.
• Note the ilieocecal valve on left
• and the appendiceal opening right.

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Polyps found on Colonoscopy

• Pedunculated Polyps
• Which of these is a
• Cancer?
• Sessile Polyps
• Which of these is a
• Cancer?

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Examples of Colon Cancer

• These are pedunculated
• malignant polyps in
• the colon.
• These are sessile
• malignant polyps in the
• colon. Note the obstruction.

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Polypectomy and Biopsy

• A polypectomy snare wire is
• shown at the right.
• Below is a pedunculated
• polyp on the left and
• the area after the polyp
• is removed on the right.

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Diverticulosis

• Examples of
• Mild, moderate and
• severe diverticulosis.
• Can you tell where the lumen
• is at on the bottom one?

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Examples of Colitis

• Moderate ulcerative
• colitis is on the left, and
• severe colitis on the
• right.
• Pseudomembranous colitis is
• shown to the right. This is due to
• a toxin from C. difficile usually
• due to the effects of antibiotics.

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Other colonoscopy findings

• Leiomyomas of the Colon.
• Benign tumors from muscle.
• The lesion on the left is
• An angiodysplasia and often
• Causes rectal bleeding but
• can be hard to find. The
• lesion on the right is a
• bleeding diverticulitis lesion.

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Summary and Questions

• Risk Category Screening
  Age to start
• Average FOBT yearly
  50 years
• Flex Sig every 5 y
• Both every 5 y
• DCBE every 5-10 y
• Colonoscopy every
  10y
• High FHx Colonoscopy every 10y 10y
  before onset
• UC Colo or Flex Sig every 1-2y
  7-10 from onset

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