Skip to Main Content

+

  • • Colorectal cancer second leading cause of cancer deaths (after lung)

    • Adenocarcinoma accounts for 95% of malignant colorectal tumors

    • Genetic predisposition in familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer (HNPCC)

    • Conditions predisposing to colorectal cancer

    • -Ulcerative colitis

      -Crohn colitis

      -Schistosomal colitis

      -Exposure to radiation

      -Presence of ureterocolostomy

    • Possible dietary influences

    • -High caloric intake

      -High saturated fat intake

      -Decreased dietary calcium

      -Decreased fiber intake

    • Carcinogenesis multi-step process involving dysfunction of tumor suppressor genes, including APC, DCC, P53

    • Distribution of colorectal cancer

    • -25% right colon

      -10% transverse colon

      -15% left colon

      -20-50% rectosigmoid colon

    • Spreads through direct extension, hematogenously, lymph nodes, transperitoneal, intraluminal

    • Synchronous lesions occur in 3-5%

++

Epidemiology

+

  • • 156,000 cases diagnosed per year

    • 65,000 colorectal cancer deaths per year

    • Incidence increases with age

    • Colon cancer is more common in women than men

    • Rectal cancer is more common in men than women

    • Multiple synchronous colonic cancers found in 5% of patients

    • 5% lifetime risk

    • 6-8% occurs before age 40 years

++

Symptoms and Signs

+

  • • Symptoms depend on anatomic location and extent of lesion

    • Right colon lesions may become large before symptoms develop

    • -May cause occult bleeding, anemia

    • Left colon lesions often cause crampy abdominal pain

    • Large bowel obstruction ~ 10% cases

    • Fatigue, weakness, vague abdominal pain, abdominal mass (< 10%), anemia

    • Constipation alternating with increased frequency of defecation

    • Dark or blood tinged stool

    • Change in stool caliber

    • Rectal cancers

    • -Hematochezia

      -Tenesmus

    • Physical exam findings may include abdominal mass, lymphadenopathy, rectal mass

++

Laboratory Findings

+

  • • Patients may have microcytic, hypochromic anemia

    • Positive occult blood on guiac stool test

    • Carcinoembryonic antigen (CEA) elevation (nonspecific, more useful for surveillance following resection), prompts additional imaging (CT scan)

    • Elevation of biochemical markers (nonspecific): CA 19-9, CA 72-4, plasma prolactin

++

Imaging Findings

+

  • • Contrast enema-filling defect, "apple core lesion"; constricted area or intraluminal mass

    Total colonoscopy: Should be performed to evaluate lesion and presence of synchronous lesions

+

  • • Ulcerative colitis

    • Crohn colitis

    • Ischemic colitis

    • Parasite infection, amebiasis

    • Diverticulitis

    • Diverticulosis

    • Appendicitis

    • Peptic ulcer disease

    • Other neoplasms of colon/rectum

    • -Lymphoma

      -Carcinoid

+

  • • Complete history (including family) and physical exam

    • Total colonoscopy with biopsy

    • Obtain plain abdominal x-ray and water-soluble contrast enema in patients with bowel obstruction

    • Once diagnosis is made, staging studies should be performed

    • -Chest x-ray

      -CT scan:Helpful to assess extramural extension or metastatic lesions

      -Liver function tests

    Endorectal US: Helpful for determining depth of invasion in rectal lesions

++

When to Admit

+

  • • Bowel obstruction/perforation

    • Hemodynamically significant lower GI bleeding

+

  • • Mainstay of management is surgical with good mechanical bowel prep

    • Lesion and regional lymphatic drainage basin need to ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessSurgery Full Site: One-Year Subscription

Connect to the full suite of AccessSurgery content and resources including more than 160 instructional videos, 16,000+ high-quality images, interactive board review, 20+ textbooks, and more.

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessSurgery

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.