Tooluniverse Cancer Variant Interpretation

Cancer Variant Interpretation for Precision Oncology

Comprehensive clinical interpretation of somatic mutations in cancer. Transforms a gene + variant input into an actionable precision oncology report covering clinical evidence, therapeutic options, resistance mechanisms, clinical trials, and prognostic implications.

KEY PRINCIPLES:

1. Report-first approach - Create report file FIRST, then populate progressively
2. Evidence-graded - Every recommendation has an evidence tier (T1-T4)
3. Actionable output - Prioritized treatment options, not data dumps
4. Clinical focus - Answer "what should we treat with?" not "what databases exist?"
5. Resistance-aware - Always check for known resistance mechanisms
6. Cancer-type specific - Tailor all recommendations to the patient's cancer type when provided
7. Source-referenced - Every statement must cite the tool/database source
8. English-first queries - Always use English terms in tool calls (gene names, drug names, cancer types), even if the user writes in another language. Respond in the user's language

LOOK UP, DON'T GUESS

When uncertain about any scientific fact, SEARCH databases first (PubMed, UniProt, ChEMBL, ClinVar, etc.) rather than reasoning from memory. A database-verified answer is always more reliable than a guess.

COMPUTE, DON'T DESCRIBE

When analysis requires computation (statistics, data processing, scoring, enrichment), write and run Python code via Bash. Don't describe what you would do — execute it and report actual results. Use ToolUniverse tools to retrieve data, then Python (pandas, scipy, statsmodels, matplotlib) to analyze it.

When to Use

Apply when user asks:

• "What treatments exist for EGFR L858R in lung cancer?"
• "Patient has BRAF V600E melanoma - what are the options?"
• "Is KRAS G12C targetable?"
• "Patient progressed on osimertinib - what's next?"
• "What clinical trials are available for PIK3CA E545K?"
• "Interpret this somatic mutation: TP53 R273H"

Input Parsing

Required: Gene symbol + variant notation (e.g., "EGFR L858R", "BRAF p.V600E", "EML4-ALK fusion", "HER2 amplification") Optional: Cancer type (improves specificity)

Parse the gene symbol and variant separately. For fusions, use the kinase partner as the primary gene. For amplifications/deletions, use the gene name directly. Normalize common aliases: HER2 -> ERBB2, PD-L1 -> CD274, VEGF -> VEGFA.

Phase 0: Tool Parameter Verification (CRITICAL)

BEFORE calling ANY tool for the first time, verify its parameters.

Workflow Overview

Input: Gene symbol + Variant notation + Optional cancer type

Phase 1: Gene Disambiguation & ID Resolution
  - Resolve gene to Ensembl ID, UniProt accession, Entrez ID
  - Get gene function, pathways, protein domains
  - Identify cancer type EFO ID (if cancer type provided)

Phase 2: Clinical Variant Evidence (CIViC)
  - Find gene in CIViC (via Entrez ID matching)
  - Get all variants for the gene, match specific variant
  - Retrieve evidence items (predictive, prognostic, diagnostic)

Phase 3: Mutation Prevalence (cBioPortal)
  - Frequency across cancer studies
  - Co-occurring mutations, cancer type distribution

Phase 4: Therapeutic Associations (OpenTargets + ChEMBL + FDA + DrugBank)
  - FDA-approved targeted therapies
  - Clinical trial drugs (phase 2-3), drug mechanisms
  - Combination therapies

Phase 5: Resistance Mechanisms
  - Known resistance variants (CIViC, literature)
  - Bypass pathway analysis (Reactome)

Phase 6: Clinical Trials
  - Active trials recruiting for this mutation
  - Trial phase, status, eligibility

Phase 7: Prognostic Impact & Pathway Context
  - Survival associations (literature)
  - Pathway context (Reactome), Expression data (GTEx)

Phase 8: Report Synthesis
  - Executive summary, clinical actionability score
  - Treatment recommendations (prioritized), completeness checklist

For detailed code snippets and API call patterns for each phase, see ANALYSIS_DETAILS.md.

Clinical Reasoning Strategies

Driver vs Passenger Reasoning

Not every mutation in a tumor is driving the cancer. Before querying databases, form a hypothesis:

• Is this gene a known oncogene or tumor suppressor? Genes like EGFR, BRAF, KRAS, TP53, PIK3CA are well-established cancer drivers. A mutation in one of these warrants deep investigation. A mutation in a gene with no known cancer role is likely a passenger.
• Is this specific mutation recurrent across tumors (hotspot)? Use cBioPortal to check. A mutation seen in hundreds of independent tumors (e.g., BRAF V600E) is almost certainly a driver. A unique, never-before-seen missense in the same gene is less certain.
• What is the predicted functional impact? Truncating mutations (nonsense, frameshift) in tumor suppressors are likely loss-of-function drivers. Missense mutations in oncogenes at known hotspot residues are likely gain-of-function drivers.
• For unique (non-hotspot) missense in driver genes, look at mechanism, not just pathogenicity. AlphaMissense gives a score; the ESMC-6B SAE composite ESM_explain_variant_mechanism(sequence=wt_protein_seq, position=..., ref_aa=..., alt_aa=..., top_k_features=5) answers how the substitution disrupts function — catalytic / ligand-binding / PTM / structural-stability loss. A unique missense that disrupts the same SAE feature category as a known driver hotspot in the same gene is more likely a driver than a missense that disrupts unrelated features. Requires ESM_API_KEY; missense only.
• Conclusion pattern: A recurrent mutation in a known driver gene is likely actionable. A unique mutation in a gene not associated with cancer is likely a passenger. State your assessment and the reasoning behind it.

Actionability Reasoning

Actionable means a therapy exists that targets this alteration. Think in tiers based on evidence strength:

• Tier 1: FDA-approved drug for this mutation in this cancer type. The standard of care — recommend confidently. Example reasoning: "CIViC returns Level A evidence, FDA label confirms indication."
• Tier 2: FDA-approved for this mutation in a different cancer type, or strong clinical trial evidence (phase 2-3) in this cancer type. Reasonable to consider, especially under tumor-agnostic approvals or with molecular tumor board discussion.
• Tier 3: Preclinical evidence only — cell line data, animal models, or case reports. May justify clinical trial enrollment but not off-label use.
• Tier 4: Biological rationale but no direct evidence — the mutation is in a druggable pathway, or a structurally similar mutation responds to therapy. Hypothesis-generating only.

When synthesizing, state the tier and explain WHY you assigned it based on the evidence you found, not just which database returned a hit.

Resistance Reasoning

If the patient has already been treated, ask: could this mutation be a resistance mechanism?