A molecular tumor board is often described as a meeting. In reality, it is a decision-making process.
The goal is not simply to review genomic findings, but to determine whether those findings should influence patient management, and if so, how. Doing that well means integrating molecular biology, pathology, clinical oncology, bioinformatics, treatment history, and the evolving scientific literature. The process is structured because genomic data alone rarely provides a complete answer.
The seven-step process
Each case moves through seven questions, asked in order. No step is skipped, and no conclusion is drawn before the one before it is settled.
Technical validation
Before discussing treatment implications, the board evaluates the reliability of the data:
- Was sequencing quality adequate?
- Is tumor purity sufficient?
- Are the reported alterations technically credible?
- Could any finding be an artefact?
- Is additional testing required?
No biological interpretation should begin until the data itself is trusted.
Biological interpretation
The next question is what is driving this tumor. Not every reported alteration is biologically important, so the board weighs:
- Driver versus passenger alterations
- Clonal versus subclonal events
- Co-occurring alterations
- Potential resistance mechanisms
- Evidence of tumor evolution
The objective is to identify the molecular events most relevant to tumor behavior.
Biomarker assessment
Genomic alterations are only part of the picture. Additional biomarkers may influence treatment decisions:
- MSI / dMMR
- Tumor mutational burden (TMB)
- Homologous recombination deficiency (HRD)
- Gene fusions
- Copy-number alterations
- RNA expression patterns
The significance of each depends on the specific tumor type and clinical setting.
Clinical context review
The same molecular finding may lead to different recommendations depending on the patient. The board reviews tumor type, disease stage, prior treatments, previous responses, current disease burden, and performance status.
Precision oncology is not applied to a mutation; it is applied to a patient.
Evidence review
Potential treatment options are evaluated using established evidence frameworks:
- Regulatory approvals
- Clinical practice guidelines
- Prospective trials
- Basket and umbrella studies
- Emerging evidence
- Biological rationale
Each recommendation is assigned a level of evidence, and the strength of that evidence is stated explicitly.
Therapeutic prioritization
Multiple options may exist simultaneously; the challenge is deciding which should come first. The board weighs expected efficacy, toxicity, availability, sequencing strategy, and future treatment opportunities.
The question is not whether a therapy can be given, but whether it should be given now.
Resistance planning
Every treatment decision includes a plan for what may happen next. The board considers known resistance pathways, potential escape mechanisms, monitoring strategies, future testing needs, and subsequent options.
Precision oncology is most effective when decisions are made one step ahead.
The MTB output
The final output is not a list of mutations. It is a structured clinical interpretation. A comprehensive report answers three fundamental questions:
Is the data reliable?
Technical validation.
What is driving the tumor?
Biological interpretation.
What should we do for this patient?
Clinical action.
These three questions form the foundation of the IYGAS Three-Layer Framework.
Why molecular tumor boards matter
Modern genomic testing can generate thousands of data points. The challenge is no longer obtaining information; it is identifying which information matters and translating it into a clinically meaningful strategy.
A molecular tumor board exists to bridge that gap, because the value of precision oncology is not measured by how many mutations are reported, but by the quality of the decisions that follow.
This content is intended for educational purposes only. It does not constitute individual medical advice and should not replace evaluation by the treating physician.