Name of the Procedure:

Oncology (breast), mRNA, microarray gene expression profiling (MammaPrint)

Summary

Gene expression profiling for breast cancer involves analyzing the activity of specific genes in cancer tissue to predict the risk of distant metastasis. This uses a technology called microarray to measure the expression levels of 70 content genes and 465 housekeeping genes from fresh frozen or formalin-fixed paraffin-embedded tissue.

Purpose

The goal is to assess the likelihood of cancer spreading to other parts of the body. This information helps oncologists determine the best course of treatment, such as the necessity of chemotherapy.

Indications

Indicated for patients with early-stage breast cancer to evaluate their risk of cancer recurrence or metastasis. Particularly useful for those with hormone receptor-positive, HER2-negative breast cancer, to tailor individualized treatment plans.

Preparation

• No special preparation is usually required from the patient.
• Ensure the tissue sample is appropriately collected and preserved (either fresh frozen or formalin-fixed paraffin-embedded).
• Previous pathology reports and patient medical history may be reviewed.

Procedure Description

1. A tissue sample, either fresh frozen or formalin-fixed paraffin-embedded, is taken from the patient's tumor.
2. RNA is extracted from the tumor cells in the sample.
3. Microarray technology is used to measure the expression levels of 70 specific content genes and 465 housekeeping genes.
4. An algorithm calculates an index score that predicts the risk of distant metastasis.

Duration

The microarray analysis and reporting typically take several days to a week.

Setting

The procedure is conducted in a specialized molecular diagnostics laboratory.

Personnel

• Pathologists to oversee tissue handling and preparation.
• Molecular biologists/technicians to perform the microarray analysis.
• Oncologists to interpret the results and determine subsequent treatment plans.

Risks and Complications

• Minimal risk associated with tissue biopsy if it's required.
• Potential for inadequate tissue sample, requiring repeat biopsy.

Benefits

• Provides valuable prognostic information.
• Helps in making more informed treatment decisions, potentially avoiding overtreatment.
• Results typically available within a week.

Recovery

• If a biopsy is performed, follow the usual post-biopsy care instructions.
• No specific recovery time is required from the profiling itself.

Alternatives

• Other gene expression profiling tests (e.g., Oncotype DX).
• Traditional clinical and pathological assessments alone.
• Pros of other tests might differ in terms of genetic markers analyzed; cons might be variability in predictive accuracy.

Patient Experience

• The main experience pertains to the biopsy if required, involving local anesthesia and mild discomfort.
• No direct discomfort from the gene expression profiling itself.
• Wait time for results can cause anxiety, which should be managed with clear communication from healthcare providers.