genoCDS

Medical Disclaimer

genoCDS is a clinical reference tool for qualified healthcare professionals only. Content is derived from published guidelines and regulatory sources and may contain errors or outdated information. It is not a substitute for professional medical judgment, institutional protocols, or individual patient assessment. Always verify recommendations against current primary sources before making clinical decisions. Full disclaimer →

Breast Cancer · Triple-Negative Breast Cancer (TNBC)

Stage Stage IIA

Tumor >4–5 cm, no nodal or distant metastasis (T2b, N0, M0). Resectable.

4 test recommendations across 1 clinical indication

At Diagnosis

Stage IIA TNBC. PDL1 CPS and BRCA1/2 germline required at diagnosis per NCCN and KEYNOTE-522.

Required 3 tests

RequiredFDA Companion Dx

PD-L1 Expression by Immunohistochemistry (IHC)

PD-L1 IHC

LOINC 85147-7

Measurement of PD-L1 (programmed death-ligand 1; CD274) protein expression on tumor cells by IHC. Reported as Tumor Proportion Score (TPS) for NSCLC. Key thresholds: TPS <1% (PD-L1 negative), TPS 1–49% (low expression), TPS ≥50% (high expression). FDA-approved companion diagnostics: 22C3 pharmDx (pembrolizumab), 28-8 pharmDx (nivolumab), SP142 (atezolizumab), SP263 (durvalumab). PD-L1 ≥50% qualifies for pembrolizumab monotherapy first-line; all TPS levels are relevant for combination chemo-immunotherapy selection.

Ordering Note

PD-L1 CPS (Combined Positive Score) ≥10 required for pembrolizumab eligibility in neoadjuvant TNBC per KEYNOTE-522. Use 22C3 antibody clone for breast cancer.

Specimen

FFPE tumor tissue (≥1% tumor)Cell block (cytology)

Evidence

FDA
FDA Approval: Pembrolizumab + Chemotherapy for High-Risk Early-Stage TNBC (KEYNOTE-522)
OncoKB Level 1NCCN Cat. 1

KEYNOTE-522: pembrolizumab + chemo significantly improved pCR and EFS in early TNBC regardless of PDL1 status, but PDL1 CPS guides metastatic use.

RequiredFDA Companion Dx

BRCA1/BRCA2 Germline Testing

BRCA1/2 Germline

LOINC 21666-3

Full sequence analysis and large rearrangement detection of BRCA1 and BRCA2 germline DNA in peripheral blood. Germline BRCA1/2 pathogenic variants found in ~5–7% of unselected breast cancer; up to 15–20% in TNBC. Eligibility criterion for PARP inhibitor therapy: olaparib (Lynparza, OLYMPIAD trial, FDA-approved 2018) and talazoparib (Talzenna, EMBRACA trial, FDA-approved 2018) for HER2− metastatic breast cancer. Also establishes hereditary risk for first-degree relatives. NCCN recommends germline testing for all metastatic breast cancer patients.

Ordering Note

Germline BRCA1/2 required in all high-risk TNBC at diagnosis. TNBC has 15-20% germline BRCA prevalence.

Specimen

Peripheral blood (EDTA)Saliva

Evidence

NCCN
NCCN Breast Cancer v2.2024
NCCN Cat. 1

NCCN Category 1: germline BRCA1/2 for all high-risk TNBC at diagnosis.

RequiredFDA Companion Dx

HER2 Testing (IHC + FISH)

HER2 IHC/FISH

LOINC 85319-2

HER2 (ERBB2) status testing by immunohistochemistry (IHC) with reflex to FISH for IHC 2+ equivocal results, per ASCO/CAP 2018 guidelines. IHC 3+ = HER2 positive. FISH amplification ratio ≥2.0 or average HER2 copy number ≥6.0 signals/cell = HER2 positive. IHC 1+ and 2+/FISH non-amplified = HER2 low (eligible for T-DXd). Required for all newly diagnosed invasive breast cancer. FDA-approved companion diagnostic for multiple HER2-targeted therapies.

Ordering Note

HER2 required to confirm triple-negative status and identify HER2-low (IHC 1+) disease.

Specimen

FFPE primary tumor tissueFFPE metastatic site

Recommended 1 test

RecommendedFDA Companion Dx

Comprehensive Solid Tumor NGS Panel

Comprehensive NGS

LOINC 81445-4

Next-generation sequencing panel covering ≥300 cancer-relevant genes, including all major NSCLC drivers (EGFR, ALK, ROS1, BRAF, KRAS, MET, RET, NTRK, HER2, FGFR), plus tumor mutational burden (TMB) and microsatellite instability (MSI). Examples include FoundationOne CDx, Tempus xT, Caris MI Transcriptome, and equivalent institutional panels. Preferred over single-gene sequential testing for efficiency and cost-effectiveness.

Specimen

FFPE tumor tissue (≥20% tumor)Liquid biopsy (ctDNA)Fresh/frozen tumor tissue

Payer Coverage

Payer Coverage Summary

Coverage status as of last policy review. Prior authorization requirements and coverage criteria may change. Verify directly with each payer before ordering.

TestMedicare (CMS)UnitedHealthAnthem BCBSHumanaCignaAetna
PD-L1 IHCCoveredCoveredCoveredCoveredCoveredCovered
BRCA1/2 GermlineCoveredCoveredCoveredCoveredCoveredCovered
HER2 IHC/FISHCoveredCoveredCoveredUnknownUnknownUnknown
Comprehensive NGSCoveredCoveredCoveredPrior AuthCoveredCovered

Coverage data last verified via automated policy research. Always confirm current policies with each payer.

Reference only. Testing guidance shown is derived from published clinical guidelines and regulatory sources. It does not constitute a clinical recommendation for any individual patient. Payer coverage information is a general summary and may not reflect current policy or individual benefit design. Full disclaimer

Recommendations on this page are derived from publicly available guidelines (NCCN, ASCO, ESMO, FDA, OncoKB) and are paraphrased for reference. They do not constitute medical advice. Evidence levels reflect the grading systems of each respective organization and should be interpreted in clinical context. This reference is updated periodically but may not reflect the most recent guideline revisions.