81525 Oncology (colon), mRNA, gene expression profiling by real-time RT-PCR of 12 genes (7 content and 5 housekeeping), utilizing formalin-fixed paraffin-embedded tissue, algorithm reported as a recurrence score

Name of the Procedure:

Oncology (colon), mRNA Gene Expression Profiling by Real-Time RT-PCR of 12 Genes (7 Content and 5 Housekeeping), Utilizing Formalin-Fixed Paraffin-Embedded Tissue, Algorithm Reported as a Recurrence Score

Summary

In simple terms, this procedure assesses gene activity in colon cancer tissues using a sophisticated technique called real-time RT-PCR. It evaluates the expression levels of 12 specific genes within the cancer cells, which helps predict the likelihood of cancer recurrence. The tissue sample is first fixed in formalin and embedded in paraffin for preservation.

Purpose

The procedure is designed to:

• Detect and measure the expression of specific genes within colon cancer tissue.
• Determine the risk of cancer returning after treatment (recurrence score).
• Aid in personalizing treatment plans based on the recurrence risk.

Indications

• Patients diagnosed with colon cancer.
• Individuals who have undergone surgical removal of colon tumors.
• Situations where a prognosis or tailored therapy is necessary to manage colon cancer.

Preparation

• No special preparations like fasting are typically needed.
• Previous diagnostic tests including biopsies and imaging might be reviewed.
• Consultation about current medications and any need for adjustments.

Procedure Description

1. A previously collected tissue sample preserved in formalin and embedded in paraffin is retrieved.
2. The sample undergoes preparation to isolate RNA.
3. Real-time RT-PCR is performed, focusing on 12 genes (7 related to cancer activity and 5 housekeeping genes).
4. Results are analyzed using an algorithm that calculates a recurrence score based on gene expression.

Duration

• The gene expression profiling process can take several hours from sample preparation to result analysis.

Setting

• The procedure is usually carried out in specialized laboratories equipped with molecular diagnostic tools.

Personnel

• Molecular biologists or clinical laboratory scientists.
• Pathologists for tissue preparation.
• Bioinformaticians to analyze and report the recurrence score.

Risks and Complications

• Minimal risk since it involves laboratory analysis of an already collected tissue sample.
• Rare instances of sample degradation or insufficient RNA quality, which might necessitate a repeat test.

Benefits

• Provides a personalized recurrence risk score.
• Helps in making informed treatment decisions.
• May better tailor therapies specific to the patient’s cancer profile.

Recovery

• No recovery needed as it is a lab-based procedure with no direct patient involvement after the biopsy.

Alternatives

• Other gene expression profiling methods.
• Traditional histological examination without gene profiling.
• Imaging techniques and other types of molecular tests.

Patient Experience

Since the procedure relies on already collected samples, the patient typically does not directly experience this procedure. Any discomfort would be associated with the initial biopsy, if that is relatively recent. Generally, there is no pain involved during the testing phase in the lab.