Tests for Prognosis Assesment
Prognostic gene test panels for breast cancer are tools that analyze the expression of specific genes in tumor cells to predict the risk of recurrence and guide treatment decisions.
These tests are done on breast cancer cells after surgery or biopsy to look at the patterns of a number of different genes. This process or test is sometimes called gene expression profiling. Based on the information gained from these tests, we can estimate the risk of disease recurrence ( prognosis) and thus tailor the treatment avoiding harmful treatments that may not benefit this particular patient. This is another form personalisation of treatment.
All breast cancer patients who are hormone positive may not benefit from chemotherapy and some of these tests can predict if the patient would benefit from the chemotherapy
Multiple panels are available commercially which examine different set of genes from 21 in Oncotype Dx to 70 genes tested in Mamma Print.
Key Prognostic Gene Test Panels
1. Oncotype DX Breast Recurrence Score
- Purpose: Evaluates the risk of distant recurrence in early-stage, ER-positive, HER2-negative breast cancer.
- Genes Tested: 21 genes (16 cancer-related genes and 5 reference genes).
- Results:
- Provides a Recurrence Score (0–100).
- Low score (0–25): Low risk; hormonal therapy alone is sufficient.
- High score (26–100): High risk; chemotherapy is recommended.
- Who Benefits: Patients with node-negative or limited node-positive (1–3 nodes) disease.
- Prognostic and Predictive: Guides both risk assessment and chemotherapy benefit.
3. Prosigna (PAM50)
- Purpose: Classifies breast cancer into molecular subtypes and predicts 10-year risk of recurrence.
- Genes Tested: 50 genes associated with tumor biology.
- Results:
- Provides a Risk of Recurrence (ROR) score (low, intermediate, or high).
- Identifies intrinsic molecular subtypes (Luminal A, Luminal B, HER2-enriched, Basal-like).
- Who Benefits: Postmenopausal women with ER-positive, HER2-negative breast cancer.
2. MammaPrint
- Purpose: Assesses the risk of distant recurrence within 10 years.
- Genes Tested: 70 genes associated with cancer aggressiveness.
- Results:
- Classifies patients as low-risk or high-risk of recurrence.
- High-risk patients may benefit from chemotherapy.
- Who Benefits: o Early-stage breast cancer patients, regardless of hormone receptor or HER2 status.
- FDA Approved: Validated for both node-negative and node-positive patients.
Comparative Features of Gene Panels
| Test | Gene Targets | Molecular Subtype Prediction | Predicts Chemo Benefit | Predicts Late Recurrence | FDA Approved |
|---|---|---|---|---|---|
|
Oncotype DX |
21 |
No |
Yes |
No |
Yes |
|
MammaPrint |
70 |
No |
Yes |
No |
Yes |
|
Prosigna |
50 |
Yes |
No |
Yes |
Yes |
|
EndoPredict |
12 |
No |
Yes |
Yes |
No |
|
BCI |
H/I ratio |
No |
No |
Yes |
No |
How Prognostic Panels Impact Treatment
1. Risk Stratification:
- Helps identify patients with low recurrence risk who can safely avoid chemotherapy.
- Identifies high-risk patients who may benefit from aggressive treatment.
2. Personalized Medicine:
- Tailors treatment to the individual's tumor biology, avoiding over- or undertreatment.
3. Long-Term Management:
- Assists in decisions regarding extended hormonal therapy for late recurrence risk.
Considerations for Using Gene Panels
- Eligibility: Not all tests are suitable for all patients. Most are limited to specific subtypes (e.g., ER-positive, HER2-negative).
- Cost and Insurance Coverage: Many tests are expensive but are often covered for eligible patients.
- Physician and Patient Preferences: Treatment decisions should integrate test results, clinical judgment, and patient preferences.
