para>The U.S. Preventive Services Task Force (USPSTF) strongly recommends that clinicians screen men and women between the ages of 50 and 75 years for CRC using fecal occult blood testing, sigmoidoscopy, or colonoscopy.
- American Cancer Society recommendations for screening include the following (2):
- Fecal occult blood testing annually
- Fecal immunochemical test (FIT) annually
- Flexible sigmoidoscopy every 5 years
- Colonoscopy every 10 years
- CT colonography every 5 years (colonoscopy completed if positive)*
- Double-contrast barium enema every 5 years*
- Stool DNA test (sDNA) every 3 years*
- *The USPSTF does not recommend barium enema as a screening test and concludes the evidence is insufficient to assess the benefits and harms of CT colonography and stool DNA testing as screening modalities for CRC.
- Screening in high-risk groups
- People with a personal history of polyps need more frequent colonoscopy screening, depending on risk (i.e., 1 or 2 <1-cm polyps with low-grade dysplasia is deemed low-risk and may warrant repeat colonoscopy in 5 to 10 years; decision is influenced by family history, age, quality of initial colonoscopy, and patient comorbidities).
- People who have a family history of CRC or adenomatous polyps before age 60 years should begin colonoscopy at age 40 or 10 years younger than the age of relative at cancer diagnosis, whichever is earlier.
- People with inflammatory bowel disease should have regular surveillance colonoscopy with biopsies to detect dysplasia; guidelines for timing and location vary by professional society but generally indicate starting surveillance by ~8 years of onset of disease followed by surveillance every 1 to 2 years.
- Genetic testing may be appropriate for individuals with a strong family history of CRC or polyps:
- Family members of a person affected by HNPCC should start colonoscopy surveillance as early as age 20 years.
- Individuals with suspected FAP should have yearly flexible sigmoidoscopy beginning at age 10 to 12 years; those who test positive for the gene linked to FAP may consider colectomy.
DIAGNOSIS
HISTORY
- Many patients with CRC are asymptomatic.
- Common presenting symptoms and signs in symptomatic patients include the following:
- Abdominal pain or cramping
- Change in bowel habits (constipation, diarrhea, narrowing of stool)
- Rectal bleeding, dark stools, or blood in stool
- Weakness or fatigue
- Anemia
- Weight loss
- Other presentations may include symptoms due to the presence of metastatic lesions (lymph nodes, liver, lung, peritoneum), fever of unknown origin, and Streptococcus bovis or Clostridium septicum sepsis.
PHYSICAL EXAM
- Weight loss
- Signs of anemia (i.e., conjunctival pallor)
- Palpable abdominal mass
DIFFERENTIAL DIAGNOSIS
- >95% of CRCs are adenocarcinomas.
- Other colonic tumors include carcinoid tumors, lymphomas, and Kaposi sarcoma in HIV.
- Many conditions can mimic CRC, including other cancers, hemorrhoids, inflammatory bowel disease, infection, and extrinsic masses (i.e., cysts, abscesses).
DIAGNOSTIC TESTS & INTERPRETATION
Initial Tests (lab, imaging)
- CBC (to evaluate anemia)
- Liver function (CRC may spread to the liver)
- Colonoscopy
- CT colography if colonoscopy incomplete
Follow-Up Tests & Special Considerations
- Carcinoembryonic antigen (CEA) should be obtained preoperatively to assist with follow-up screening.
- CT to evaluate presence of metastatic disease
- Chest x-ray to evaluate presence of chest metastases
- Endoscopic ultrasound (EUS) may be used to evaluate the extent of rectal cancers; endorectal MRI may also provide further detail.
- Intraoperative US may be used to evaluate solid organs (e.g., the liver) after tumor resection.
- Positron emission tomography (PET) may be used in some cases to detect metastatic disease.
Diagnostic Procedures/Other
- Biopsy is usually performed (most often during colonoscopy) if CRC is suspected.
- CT needle-guided biopsy may be needed to evaluate a suspected tumor or metastasis.
Test Interpretation
The American Joint Committee on Cancer (AJCC) TNM staging is preferred
- Stage 0: limited to the mucosa (carcinoma in situ or intramucosal carcinoma (Tis, N0, M0)
- Stage I: invades mucosa (T1) or muscularis propria (T2); no invasion of lymph nodes or distant sites (T1, N0, M0 or T2, N0, M0)
- Stage IIA: invades pericolorectal tissues; no lymph nodes or distant sites (T3, N0, M0)
- Stage IIB: penetrates to surface of visceral peritoneum; no lymph nodes or distant sites (T4a, N0, M0)
- Stage IIC: directly invades or adherent to other organs or structures (T4b, N0, M0)
- Stage IIIA: invades submucosa or muscularis propria with spread to 1 to 3 lymph nodes; no distant sites (T1, N1, M0 or T2, N1, M0)
- Stage IIIB: invades pericolorectal tissues or surface of visceral peritoneum + spread to 1 to 3 lymph nodes; no distant sites (T3, N1, M0, or T4a, N1, M0)
- Stage IIIC: invades pericolorectal tissues or peritoneum or other organs and to ≥4 nearby lymph nodes; no distant sites (any T3 or T4, N2, M0)
- Stage IVA: any level of invasion with spread to one organ or site (any T, any N, M1a)
- Stage IVB: any level of invasion with spread to more than one organ or site or peritoneum (any T, any N, M1b)
TREATMENT
MEDICATION
Surgical resection is the primary treatment for CRC, as noted in the following texts. Adjuvant chemotherapy is most clearly beneficial for stage III (node-positive) disease, in which improvements of ~30% may be achieved in both disease recurrence and overall survival, compared with nontreated controls. Chemotherapeutic regimens for metastatic disease may extend overall survival from 6 months to ~2 years (3)[B].
First Line
Combination chemotherapy is common and may include oxaliplatin, irinotecan, fluorouracil, leucovorin, and capecitabine.
Geriatric Considerations
Elderly patients tend to tolerate CRC chemotherapy and should be considered for treatment.
Second Line
Targeted therapies may be used alongside first-line agents or alone if first-line agents are ineffective
- Bevacizumab (Avastin) is a monoclonal antibody that targets vascular endothelial growth factor (VEGF); inhibits angiogenesis
- Cetuximab (Erbitux) and panitumumab (Vectibix) are monoclonal antibodies that target epidermal growth factor receptor (EGFR).
- Aflibercept and regorafenib are newer agents with actions on VEGF.
SURGERY/OTHER PROCEDURES
- Surgery is the primary treatment for localized CRC
- May involve segmental resection, hemicolectomy, or colectomy, as well as resection of nodes, depending on size and invasion
- Laparoscopic-assisted colectomy is an emerging option for earlier stage tumors.
- Surgery for rectal cancer may include local transanal, low anterior, or abdominoperineal resection or pelvic exenteration.
- Radiation therapy is most often used for peritoneal or rectal cancers; it may also be used to relieve symptoms.
COMPLEMENTARY & ALTERNATIVE MEDICINE
- May serve as an adjunct to treatment for CRC
- 70-75% of cancer survivors report using at least one type of complementary and alternative medicine (CAM), and almost all report that the alternative therapy improved well-being.
ONGOING CARE
FOLLOW-UP RECOMMENDATIONS
Patient Monitoring
- People with a personal history of proximal cancer (nonrectal) should have follow-up colonoscopy in 1 year and, if normal, in 3 and 5 years subsequently.
- CEA and/or CA 19-9 are used to detect recurrence in people treated for CRC. (Note: CEA levels may be elevated in ulcerative colitis, nonmalignant GI tumors, liver disease, lung disease, and in smokers.)
PATIENT EDUCATION
- NIH: Colorectal cancer: http://www.nlm.nih.gov/medlineplus/colorectalcancer.html
- NCI: Colorectal cancer: http://www.cancer.gov/types/colorectal
- AAFP: Colorectal Cancer: http://www.aafp.org/afp/2015/0115/p93-s1.html
PROGNOSIS
5-year relative survival rate is determined by stage (adjusted for patients dying of other diseases): stage I: 93%; stage II: 72-85%; stage III: 44-83%; stage IV: 8%.
COMPLICATIONS
- Colorectal surgery: pain, deep vein thrombosis, anastomotic leaks, infection, scarring, bowel obstruction
- Chemotherapy: hair loss, nausea, vomiting, bruising, fatigue, increased risk for infections
- Radiation therapy: skin irritation, nausea, rectal pain, incontinence, bladder irritation, fatigue, and sexual problems
REFERENCES
11 Siegel RL, Miller KD, Jemal A. Cancer statistics, 2015. CA Cancer J Clin. 2015;65(1), 5-29.22 American Cancer Society. Guidelines for the early detection of cancer. http://www.cancer.orghealthy/findcancerearly/cancerscreeningguidelinesamericancancer-society-guidelines-for-the-earlydetection-ofcancer. Accessed 2015.33 Brenner H, Kloor M, Pox CP. Colorectal cancer. Lancet. 2014;383(9927):1490-1502.
ADDITIONAL READING
- Benson ABIII, Venook AP, Bekaii-Saab T, et al. Colon cancer, version 3.2014. J Natl Compr Canc Netw. 2014;12(7):1028-1059.
- National Institutes of Health, National Cancer Institute. Colorectal Cancer-for patients. http://www.cancer.gov/types/colorectal/. Accessed 2015.
CODES
ICD10
- C19 Malignant neoplasm of rectosigmoid junction
- C18.9 Malignant neoplasm of colon, unspecified
- C20 Malignant neoplasm of rectum
- Z12.11 Encounter for screening for malignant neoplasm of colon
- Z86.010 Personal history of colonic polyps
- Z12.12 Encounter for screening for malignant neoplasm of rectum
- C18.8 Malignant neoplasm of overlapping sites of colon
ICD9
- 154.0 Malignant neoplasm of rectosigmoid junction
- 153.9 Malignant neoplasm of colon, unspecified site
- 154.1 Malignant neoplasm of rectum
- V76.51 Special screening for malignant neoplasms of colon
- V12.72 Personal history of colonic polyps
- 154.8 Malignant neoplasm of other sites of rectum, rectosigmoid junction, and anus
SNOMED
- 93980002 Primary malignant neoplasm of rectosigmoid junction
- 93761005 Primary malignant neoplasm of colon
- 93984006 Primary malignant neoplasm of rectum
- 275978004 Screening for malignant neoplasm of colon
- 425178004 Adenocarcinoma of rectosigmoid junction (disorder)
- 92695008 Carcinoma in situ of rectosigmoid junction (disorder)
- 363414004 malignant tumor of rectosigmoid junction (disorder)
- 428283002 history of polyp of colon (situation)
CLINICAL PEARLS
- The USPSTF recommends screening beginning at age 50 years and notes that evidence supports fecal occult blood testing (yearly), sigmoidoscopy, or colonoscopy (every 10 years).
- High-risk polyp findings include multiple polyps, villous polyps, and larger polyps; hyperplastic polyps are less likely to become cancerous.
- 10% of cases of CRC occur in people <50 years of age. People who have a family history of CRC without other risks (i.e., polyposis syndrome) should begin colonoscopy at age 40 years or 10 years younger than the age of relative at cancer diagnosis, whichever is earlier.
- Iron deficiency anemia in the elderly should prompt a search for CRC and should not be attributed to normal aging.