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Apr 5, 2017 11:56AM
Apr 5, 2017 04:13PM
In my post above, I noted:
"In some cases (but not always), a second multiparmeter test might be ordered (e.g., MammaPrint plus BluePrint, Prosigna), if under applicable criteria (including "Clinical Risk" for MammaPrint) such further testing may provide additional information of value to decision-making. However, such secondary testing is not always recommended and appears to be less common outside of the United States."
Patients who do receive such secondary testing may or may not receive a clear signal.
MammaPrint: Is it black and white?
Please confirm the following with a professional. MammaPrint may have a "binary" output (High Risk or Low Risk), but as a result of the design of the MINDACT trial and the available 5-year results pertaining to "discordant" groups, the test appears appears to yield less clear information in many patients.
Results from the MINDACT trial with 5 years of follow-up were recently published (Cardoso (2016)). This is a highly detailed and technical publication, so I refer others to the original. The documents can be accessed here:
Main Page: http://www.nejm.org/doi/full/10.1056/NEJMoa1602253
PDF version (Free): http://www.nejm.org/doi/pdf/10.1056/NEJMoa1602253
Supplementary Appendix (Free): http://www.nejm.org/doi/suppl/10.1056/NEJMoa1602253/suppl_file/nejmoa1602253_appendix.pdf
Hunter perspective (2016) (Free): http://www.nejm.org/doi/pdf/10.1056/NEJMp1608282
Hudis editorial (2016): http://www.nejm.org/doi/pdf/10.1056/NEJMe1607947
(Available for purchase)
The MINDACT trial design incorporated two risk classifications. It used a Clinical Risk Classification (using a MODIFIED version of Adjuvant! Online) to assign clinical risk as either "Clinical Low Risk" or "Clinical High Risk". It used a Genomic Risk Classification (using the MammaPrint test result) to assign genomic risk as "Genomic Low Risk" or "Genomic High Risk".
This yielded four different study groups (MP = MammaPrint):
(a) Clinical Low / Genomic MP Low
(b) Clinical High / Genomic MP Low ("discordant")
(c) Clinical Low / Genomic MP High ("discordant")
(d) Clinical High / Genomic MP High
The group that is Low Risk by both criteria (Group (a)) and the group that is High Risk by both criteria (Group (d)) are "concordant" (same: Low Low or High High).
The two groups that have different clinical and genomic risks (one Low and one High) are "discordant" (Groups (b) and (c)).
Part of the study looked at whether directing chemotherapy decisions on the basis of genomic risk or on the basis of clinical risk led to any difference in distant recurrences in the "discordant" groups. In certain groups, the test was not found to give a very clear signal regarding the potential benefit of added chemotherapy, (although due to differences in risk tolerance, patients may have differing views on this). The study had some limitations. For example, the study was not adequately powered to demonstrate the statistical significance of some differences between groups for all endpoints. (A medical oncologist should be able to explain possible caveats arising from these limitations.) In any event, the clarity of the information provided by the test and the medical advice received in light of same, will likely differ according to these groupings.
Prosigna: Some cases appear to yield an "Intermediate" result
Please confirm it with a professional, but it appears the Prosigna test may in some situations provide an "Intermediate" risk output. The following screen shot is taken from the Package Insert, which seems to suggest that test outputs differ by Risk Category, and that the test yields "Low, Intermediate, High" outputs in the node-negative setting.
Of course, patients should never hesitate to inquire with their medical oncologist about such additional testing.
Stage IA IDC, 9/2013 BMX. Right: IDC (1.5 mm, grade 2) with DCIS (5+ cm), 0/4 nodes, pN0. Left: DCIS (5+ cm), 0/1 node, pN0(i+).