Tumor Gene Expression Profiling To Predict Risk of Breast Cancer Recurrence: EGAPP™ Recommendation
The majority of women treated for early stage breast cancer (stage I/II, node-negative) will remain disease-free at 10 years without undergoing chemotherapy treatment. This is especially true for women with estrogen-receptor positive breast cancer treated with tamoxifen. However, some of these women will experience a recurrence of their disease (cancer coming back), which may be prevented with chemotherapy.
The activity (expression) of specific genes within breast tumor cells has been found to be associated with the chance of disease recurrence. Several gene expression profiles (GEPs) are clinically available that provide variations on “recurrence risk scores” intended to help doctors and their patients in treatment decision making. Knowledge of breast cancer GEP recurrence risk score could possibly help identify those women most likely to benefit from chemotherapy. The EGAPP™ Working Group examined the scientific evidence to see whether gene expression profiling is valid and useful for this purpose.
EGAPP™ Recommendation Statement
Summary of Findings on Gene Expression Profiling To Predict Risk for Breast Cancer Recurrence
In 2009, the independent Evaluation of Genomic Applications in Practice and Prevention (EGAPP™) Working Group determined that there was not enough evidence to state whether breast cancer GEP should or should not be used for early stage breast cancer treatment decision making. The balance of benefits and harms of using breast cancer GEP could not be determined from the available evidence.
The EGAPP recommendation was based on the following key points from the evidence review:
- The EGAPP™ Working Group (EWG) found no direct or indirect evidence linking tumor gene expression profiling of women with breast cancer to improved health outcomes.
- For one test, the EWG found preliminary evidence of potential benefit of testing results to some women who face decisions about treatment options (reduced adverse events due to low risk women avoiding chemotherapy), but could not rule out the potential for harm for others (breast cancer recurrence that might have been prevented).
- The EWG encourages further development and evaluation of these technologies.
For the General Public
For Health Professionals
Estrogen-receptor positive breast cancer
In women with estrogen receptor-positive cancers, cancer cell growth is fed by estrogen. Such cancers are often treated with tamoxifen, because tamoxifen blocks the uptake of estrogen, slowing cancer cell growth.
Definition adapted from: National Cancer Institute
Gene Expression Profiles (GEPs)
Breast cancer gene expression profiles (GEPs) look at the activity of genes within breast tumor tissue samples. Certain patterns of gene activity are linked to a greater chance of breast cancer recurrence. GEPs do not look for genetic changes that are passed down in families (inherited).