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Test ID FOBT Fecal Occult Blood, Colorectal Cancer Screen, Qualitative, Immunochemical, Feces

Reporting Name

Occult Blood, QL, Immunochemical, F

Useful For

Colorectal cancer screening

 

Screening for gastrointestinal bleeding

 

This test has not been validated for testing of patients with hemoglobinopathies.

Specimen Type

Fecal


Advisory Information


This test will not detect upper gastrointestinal bleeding. If clinically indicated, order HQ / HemoQuant, Feces.



Specimen Required


Supplies: Fecal Occult Blood Test Kit (T682)

Container/Tube: Fecal Occult Blood Test Kit

Specimen Volume: Specimen must fill the grooved portion of the sample probe
Collection Instructions:

1. Collect a random stool specimen.

2. See Fecal Occult Blood Test Kit package insert for instructions.

3. Specimen must be collected in specific sample vial within 4 hours of defecation.


Specimen Minimum Volume

See Specimen Required

Specimen Stability Information

Specimen Type Temperature Time Special Container
Fecal Refrigerated (preferred) 30 days FOBT
  Ambient  15 days FOBT

Reference Values

Negative

 

This test has not been validated in a pediatric population, results should be interpreted in the context of the patient's presentation.

Test Classification

This test has been cleared, approved or is exempt by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information

82274

G0328-Government payers (if appropriate)

LOINC Code Information

Test ID Test Order Name Order LOINC Value
FOBT Occult Blood, QL, Immunochemical, F 29771-3

 

Result ID Test Result Name Result LOINC Value
FOB Occult Blood, Fecal 29771-3

Clinical Information

Colorectal cancer (CRC) is one of the most commonly diagnosed cancers in the United States, and the second leading cause of cancer-related deaths. CRC almost always develops from adenomatous polyps, yet patients remain asymptomatic until the cancer progresses to a fairly advanced stage. Screening for colorectal cancer is strongly advocated for by the United States Preventive Services Task Force, the American Cancer Society, the American College of Gastroenterology, and other clinical societies, due to the high incidence of disease and decrease in mortality with medical intervention. Men and women at average risk for colorectal cancer should be screened at regular intervals beginning at age 50 and continuing until age 75. Individuals with certain high-risk factors (age, African-American race, inflammatory intestinal disorders, family history of colon cancer, obesity, diabetes, poor diet) may consider earlier screening strategies.

 

A variety of options are available for colorectal cancer screening including: fecal occult blood testing, sigmoidoscopy, colonoscopy, and multimarker Cologuard testing that includes genetic markers of colorectal cancer. Historically occult blood tests utilized guaiac-based tests that were susceptible to dietary interferences, but this test utilizes fecal immunochemical testing (FIT) specific for human hemoglobin, eliminating the need for dietary and medication restrictions. For colorectal cancer screening, only a single collection is required. The specificity of FIT is routinely greater than 95% with reported sensitivities ranging from 40% to 70% based on the patient population. The clinical specificity of FIT is 97% based on internal studies conducted at Mayo Clinic but can be limited by gastrointestinal bleeding from a non-colorectal cancer source. In a recent study of 10,000 average risk participants, Cologuard detected colorectal cancer, precancerous lesions, and polyps with high-grade dysplasia with higher sensitivity than FIT testing.(1) However, Cologuard had slightly lower specificity than FIT testing in that study. Cologuard requires an entire bowel movement for testing versus 1 small sample for FIT. Current societal guidelines endorse the use of FIT and Cologuard interchangeably with 1-year based screening for FIT versus a suggested 3-year DNA based screening for average risk population, recognizing that the testing interval for the latter is uncertain.(2,3)

Interpretation

This is a quantitative assay but results are reported qualitatively as negative or positive for the presence of fecal occult blood; the cutoff for positivity is 100 ng/mL hemoglobin. The following comments will be reported with the qualitative result for patients older than 17 years:

-Positive results; further testing is recommended if clinically indicated. This test has 97% specificity for detection of lower gastrointestinal bleeding in colorectal cancer.

-Negative results; this test will not detect upper gastrointestinal bleeding; HQ / HemoQuant, Feces test should be ordered if clinically indicated.

Clinical Reference

1. Imperiate TF, Ransohoff DF, Itzkowitz SH, et al: Multitarget stool DNA testing for colorectal-cancer screening. N Engl J Med 2014;370(14):1287-1297

2. Robertson DJ, Lee JK, Boland CR, et al. Recommendations on fecal immunochemical testing to screen for colorectal neoplasia: A consensus statement by the US Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2017;152(5):1217-1237

3. Rex DK, Boland CR, Dominitz JA, et al. Colorectal cancer screening: Recommendations for physicians and patients from the U.S. Multi-Society Task Force on Colorectal Cancer. Gastroenterology. 2017 Jul;153(1):307-323. doi: 10.1053/j.gastro.2017.05.013

4. Levin B, Lieberman DA, McFarland B, et al: Screening and Surveillance for the Early Detection of Colorectal Cancer and Adenomatous Polyps, 2008: A Joint Guideline from the American Cancer Society, the US Multi-Society Task Force on Colorectal Cancer, and the American College of Radiology. CA Cancer J Clin 2008 May-June;58(3):130-160. doi: 10.3322/CA.2007.0018

5. Whitlock EP, Lin JS, Liles E, Beil TL, Fu R: Screening for colorectal cancer: a targeted, updated systematic review for the U.S. Preventive Services Task Force. Ann Intern Med 2008 Nov 4;149(9):638-658

6. Hol L, Wilschut JA, van Ballegooijen M, et al: Screening for colorectal cancer: random comparison of guaiac and immunochemical faecal occult blood testing at different cut-off levels. Br J Cancer 2009 Apr 7;100(7):1103-1110. doi: 10.1038/sj.bjc.6604961

7. Levi Z, Rozen P, Hazazi R, et al: A quantitative immunochemical fecal occult blood test for colorectal neoplasia. Ann Intern Med 2007 Feb 20;146(4):244-255

8. Tannous B, Lee-Lewandrowski E, Sharples C, et al: Comparison of conventional guaiac to four immunochemical methods for fecal occult blood testing: implications for clinical practice in hospital and outpatient settings. Clin Chem Acta 2009 Feb;400(1-2):120-122. doi: 10.1016/j.cca.2008.10.023

Method Name

Immunochemical