AI Figures Out Meaning of MolDx DCIS Proposed LCD... and Meaning of MolDx term, "Rhetorical Proof"

 MolDx received a request to cover the molecular test DCISion RT (or Oncotype DCIS SCORE).   My impresssion is, MolDx has done an extensive write up culminating in a decision no current tests are covered.   Assume you do not know the answer, and read the LCD carefully to determine the answer.  Explain what is going on, in this document.

ORIGINAL BLOG   https://www.discoveriesinhealthpolicy.com/2025/07/new-clia-policies-at-cms-new-moldx.html

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AI Summary of the LCD’s Position on DCISionRT / Oncotype DCIS Score

Bottom Line:

MolDx currently does not cover DCISionRT or Oncotype DX DCIS Score (or any similar test) for DCIS risk stratification to guide radiation therapy decisions. 

The LCD gives an extensive analysis of the current state of evidence and concludes that no test today meets the reasonable and necessary standard. 

However, MolDx leaves the door open for future coverage if better evidence is provided.

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Explanation of What's Going On in This LCD:

1. What Is the Request?
   MolDx reviewed requests to cover molecular tests for DCIS patients that would allow physicians to safely omit radiation therapy (RT) in women identified as "low risk" for recurrence.

2. MolDx’s Current Coverage Policy (as stated explicitly in the LCD):
   These tests are not covered because no test currently meets MolDx's standards for being reasonable and necessary. Specifically, the tests have not sufficiently demonstrated that they outperform existing clinical risk tools (such as MSKCC nomograms or VNPI) in accurately identifying patients who will have less than 5% absolute benefit from radiation.

3. Criteria MolDx Would Require for Future Coverage (if evidence improved):
   MolDx lays out precise future requirements:

• The patient must meet strict criteria (DCIS only, no mastectomy, no prior RT, clear decision pathways regarding RT).

• The test must have completed technical validation.

• The test must demonstrate it identifies low-risk patients better than existing tools.

• Low-risk is defined as ≤5% absolute benefit from RT in reducing ipsilateral breast tumor recurrence (IBTR).

4. Why Current Evidence Fails:
   MolDx provides an exhaustive review of studies on both DCISionRT and Oncotype DX DCIS Score. Their critiques are:

• Sample sizes too small for strong statistical confidence, especially in the low-risk groups.

• Outcomes inconsistent across studies.

• Current studies show relative risk reductions from RT persist, even in "low-risk" groups, though they may not reach statistical significance because of small numbers.

• No test has clearly shown incremental value over existing clinicopathologic tools.

• Newer modifications to the tests (e.g., DCISionRT's new 2.8 cutoff) are not yet externally validated.

5. The Larger Context MolDx Recognizes:

• Radiation therapy in DCIS is already somewhat overused; Medicare patients (older) may be particularly good candidates for avoiding RT.

• There is clinical utility in tests that could accurately identify patients for whom RT provides negligible benefit.

• Shared decision-making is complex, and having clear tools might reduce overtreatment.

6. Why MolDx Isn’t Convinced Yet:
   MolDx believes:

• Clinicopathologic tools already provide reasonable stratification.

• Biomarker tests haven’t clearly surpassed these tools in accuracy.

• The current data supporting these tests are too weak, too heterogeneous, and sometimes underpowered.

7. Additional Notes:
   MolDx explicitly mentions that clinicians and patients might be misled if a test shows any risk reduction from RT (even small), because current behavior trends toward giving RT if any benefit is suggested. Therefore, the test must demonstrate a very clear lack of meaningful benefit (≤5% absolute risk reduction) to shift behavior safely.

8. Contractor Advisory Committee (CAC) Feedback:
   CAC members expressed that a good test would be useful, but the current evidence is inadequate. Some providers already use these tests, but there’s no consensus on their validity.

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Summary of MolDx’s Position in Plain Terms:

MolDx sees potential value in biomarker tests for DCIS, but today’s tests haven’t convincingly proven that they add enough to what we already know from existing clinical tools. Until there’s stronger, clearer, and validated evidence (especially demonstrating <5% absolute RT benefit for "low-risk" patients), MolDx will not cover these tests.

They explicitly state they are open to changing this position with better future evidence.

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What does MolDx mean by RHETORICAL PROOF?

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The phrase "rhetorical proof" is unusual in a medical policy document, but here's what MolDx likely means by it, given the context:

Contextual Meaning in This LCD:

MolDx writes that some advocates of DCISionRT argue it identifies patients who have no relative risk reduction from RT, and that this is valuable because it provides proof for physicians and patients to confidently omit RT. However, MolDx says there is no convincing evidence yet that any test identifies such a population with certainty.

MolDx comments:

"While it is desirable to have a tool that identifies a population with no relative risk reduction from RT ... we conclude that there is insufficient data currently to convincingly support the assertion... This was a central rationale presented at the CAC by SMEs for use of such tests, yet this assertion is most easily explained by a failure to identify statistical significance... While Vicini’s reanalysis... seemingly greatly improves the test... these data cannot reasonably be interpreted as evidence... but raise concern... underpowered..."

What MolDx Likely Means by "Rhetorical Proof":

"Rhetorical proof" here seems to mean something persuasive in clinical conversation but not scientifically proven. That is:

• It might help a doctor convince a patient or defend a decision to omit RT.

• It might sound like proof ("this test says you are so low risk you need no RT").

• But it's not scientifically robust proof in the evidentiary sense MolDx requires (validated, statistically sound, externally confirmed).

So "rhetorical proof" is used a bit cynically here. MolDx is criticizing the notion that these tests offer a convenient talking point rather than hard, validated science. It’s persuasive rhetoric for doctors and patients but doesn’t meet the Medicare standard of "reasonable and necessary."

In Plain Terms:

MolDx is saying:

Just because a test helps a doctor feel better saying, "See, you don’t need RT," doesn’t make it scientifically justified or covered by Medicare. That’s rhetoric, not evidence.