1. What if my breast cancer does not meet a multiparameter gene expression test's criteria?
If it does not, then that particular test would not be able to be used. Future research findings may support a test's use in additional patient populations, but currently the criteria are matched with the test's supporting data. There are guidelines fully established for each of the multiparameter assays.
2. Should I have more than one multiparameter gene expression test done?
This would not generally be necessary. Even though the currently available tests evaluate different combinations of genes, their findings are all intended to stratify breast cancer recurrence risk or response to treatment.
3. Can a blood test be used to perform a multiparameter gene expression test?
Blood tests can be used to evaluate other aspects of breast cancer but cannot be used to perform multiparameter gene expression tests. What is being evaluated is the tumor's likely behavior, so the test requires tumor tissue and cells. Blood tests are more specific for detecting genes involved in hereditary breast cancer syndromes (i.e., BRCA1, BRCA2). The multiparameter gene expression tests identify changes in genes that have occurred only in the tumor, while blood tests currently test normal blood cells and so detect inherited gene changes that occur in all cells in the body.