Name of the Procedure:

Oncology (breast), mRNA, gene expression profiling by real-time RT-PCR of 11 genes (7 content and 4 housekeeping), utilizing formalin-fixed paraffin-embedded tissue, with algorithms reported as percentage risk for metastatic recurrence and likelihood of benefit. Common names include Breast Cancer Gene Expression Profiling or Breast Cancer mRNA Profiling.

Summary

This medical procedure analyzes the expression levels of specific genes in a breast cancer tumor sample to estimate the risk of cancer recurrence and the potential benefit of chemotherapy. The analysis uses a special technique called real-time reverse transcription polymerase chain reaction (RT-PCR) on tissue samples that have been preserved in formalin and embedded in paraffin.

Purpose

The primary purpose of this procedure is to help guide treatment decisions for patients with breast cancer by predicting the risk of cancer returning and assessing the potential benefit of chemotherapy.

Indications

• Patients with early-stage breast cancer.
• Individuals with tumors that are hormone receptor-positive (HR+).
• Cases where deciding the benefit of chemotherapy is critical.

Preparation

• No special preparation like fasting is required.
• Collection of a biopsy sample of the tumor, which is usually done as part of the initial diagnosis.

Procedure Description

1. A small sample of the tumor, preserved in formalin and embedded in paraffin, is obtained.
2. The sample is processed to isolate mRNA.
3. Real-time RT-PCR is used to measure the expression levels of 11 genes (7 content genes and 4 housekeeping genes).
4. An algorithm calculates the percentage risk of metastatic recurrence and the likelihood of benefit from chemotherapy based on the gene expression data.

Duration

The laboratory analysis typically takes a few days, although sample preparation and result interpretation may extend over a couple of weeks.

Setting

The procedure is conducted in a specialized laboratory, but the initial biopsy sample is usually taken in a hospital or outpatient clinic.

Personnel

• Pathologists to prepare and examine the tissue sample.
• Laboratory technicians and molecular biologists for the RT-PCR analysis.
• Oncologists to interpret the results and discuss the findings with the patient.

Risks and Complications

• Minimal risk as it's a non-invasive lab test on a pre-existing sample.
• Rare risk of sample contamination or technical issues leading to inconclusive results.

Benefits

• Provides personalized risk assessment for cancer recurrence.
• Helps in making informed decisions about the benefit of chemotherapy.
• Can lead to more tailored and effective treatment plans.

Recovery

• No recovery period is associated with the gene expression profiling itself.
• Follow-up appointments with the oncologist to discuss the results and next steps.

Alternatives

• Other genomic tests or oncotype assays which might evaluate different sets of genes or markers.
• Traditional clinical-pathologic factors without genomic profiling, though less personalized.

Patient Experience

Patients do not directly experience the gene expression profiling process; however, they will meet their oncologist to discuss the results. The consultation will focus on risk assessment and treatment planning.