Name of the Procedure:

Oncology (colorectal) screening, quantitative real-time target and signal amplification of 10 DNA markers, fecal hemoglobin analysis utilizing stool sample. Common name: Colorectal Cancer Screening Test.

Summary

This screening test detects colorectal cancer by analyzing stool samples for specific DNA markers and the presence of blood. It identifies mutations in the KRAS gene and methylation changes in NDRG4 and BMP3 genes, alongside measuring fecal hemoglobin, and reports results as positive or negative.

Purpose

This test aims to identify early signs of colorectal cancer. By detecting cancer-related genetic changes and blood in the stool, it can help in diagnosing colorectal cancer at an early, more treatable stage.

Indications

• Adults aged 50 and older
• Individuals with a family history of colorectal cancer
• Patients exhibiting symptoms like persistent abdominal pain, changes in bowel habits, or blood in the stool
• Patients with previous polyps or a history of colorectal disease

Preparation

• No special diet or medication changes are necessary before the test.
• Patients should follow instructions provided for collecting the stool sample to avoid contamination.

Procedure Description

1. Collection: Patients collect a stool sample using a provided kit.
2. Analysis: In the lab, the stool sample undergoes quantitative real-time PCR to amplify 10 specific DNA markers.
   • DNA Markers: KRAS mutations and the promoter methylation of NDRG4 and BMP3 are targeted.
3. Hemoglobin Testing: The presence of fecal hemoglobin is also tested using immunochemical methods.
4. Algorithm: An algorithm integrates DNA marker results and hemoglobin levels to report the result as positive or negative.

Duration

The procedure typically takes a few minutes for sample collection; lab analysis takes several days.

Setting

The stool sample collection is done at home. The analysis is conducted in a specialized laboratory.

Personnel

• Laboratory technicians and molecular biologists conduct the analysis.
• Primary care physicians or gastroenterologists communicate the results to patients.

Risks and Complications

• No direct risks from stool sample collection.
• Rare chance of sample contamination, requiring a repeat test.

Benefits

• Early detection of colorectal cancer and pre-cancerous polyps.
• Non-invasive and simple to perform at home.
• Provides peace of mind or informs further diagnostic steps.

Recovery

• No recovery needed since the procedure is non-invasive.

Alternatives

• Colonoscopy: More invasive but provides definitive results and the ability to remove polyps during the procedure.
• Fecal Immunochemical Test (FIT): Only detects blood in the stool, simpler but less comprehensive.
• CT Colonography: Non-invasive imaging but involves radiation exposure.

Patient Experience

• Minimal discomfort during stool collection.
• Anxiety while waiting for results can be managed by discussing expectations with healthcare providers.
• If results are positive, follow-up procedures like a colonoscopy might be recommended.