Multigene Panel Testing is the Recommended Platform for Hereditary Cancer Risk Assessment
For hereditary cancer genetic testing, use multigene panel testing (MGPT) via next-generation sequencing (NGS) that includes all relevant genes for the patient's specific cancer type, as outlined in current ASCO and NCCN guidelines 1.
Specific Gene Selection Based on Cancer Type
The choice of which genes to include depends on the patient's cancer diagnosis. At minimum, all panels should include BRCA1, BRCA2, and Lynch syndrome genes (MLH1, MSH2, MSH6, PMS2, EPCAM) given their prevalence and importance across multiple cancer types 1.
Strongly Recommended Genes by Cancer Type:
- Breast Cancer: BRCA1, BRCA2, PALB2, TP53, CDH1, PTEN, STK11 1
- Colorectal Cancer: APC, EPCAM, MLH1, MSH2, MSH6, MUTYH, PMS2, TP53, POLD1, POLE 1
- Endometrial Cancer: EPCAM, MLH1, MSH2, MSH6, PMS2, PTEN, STK11 1, 2
- Ovarian Cancer: BRCA1, BRCA2, BRIP1, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, RAD51C, RAD51D 1
- Pancreatic Cancer: ATM, BRCA1, BRCA2, CDKN2A, EPCAM, MLH1, MSH2, MSH6, PALB2, PMS2, STK11, TP53 1
- Prostate Cancer: BRCA1, BRCA2, EPCAM, HOXB13, MLH1, MSH2, MSH6, PMS2 1
Why Multigene Panels Over Sequential Testing
MGPT is more efficient than sequential single-gene testing because it simultaneously analyzes multiple genes, provides faster results for treatment decisions, and may be more cost-effective when insurance covers only one testing episode 1. The 2024 ASCO guideline explicitly recommends testing all relevant genes simultaneously rather than using a sequential approach 1.
Technical Performance Standards:
NGS-based multigene panels achieve:
- >99% of bases covered at >30x read depth 3
- Analytical sensitivity >99.92% 4
- 100% concordance with Sanger sequencing for variant detection 4
Critical Caveats About Panel Size
Avoid unnecessarily large comprehensive cancer panels that include genes with uncertain clinical validity or low penetrance unless specifically indicated 1, 2. Larger panels increase:
- Variants of uncertain significance (VUS) that complicate interpretation 1, 2
- Risk of misinterpretation and potential overtreatment 1
- Incidental findings requiring additional counseling 5
The ASCO guideline specifically addresses this concern, recommending focused panels that include genes informed by personal and family history rather than indiscriminate broad testing 1.
When to Consider Broader Testing
Expand beyond syndrome-specific panels when:
- Personal and family history suggests multiple possible syndromes 1
- Previous limited testing was negative but clinical suspicion remains high 2, 6
- Tumor genomic profiling identified a pathogenic variant requiring germline confirmation 1
- Patient has only one opportunity for insurance-covered testing 1
Practical Implementation
Work with laboratories offering CLIA-certified, CAP-accredited NGS platforms 4. Common commercial platforms include those offering 25-94 gene panels specifically validated for hereditary cancer 3, 4. The specific brand matters less than ensuring the panel includes all guideline-recommended genes for your patient's cancer type 1, 2.
Quality Metrics to Verify:
- Panel includes deletion/duplication analysis (not just point mutations) 4
- Laboratory provides variant classification following ACMG/AMP guidelines
- Turnaround time supports clinical decision-making needs 1
Special Populations
For patients with tumor testing showing mismatch repair deficiency, germline testing should still be performed regardless of tumor results 1. Approximately 34.5% of Lynch syndrome patients would be missed without germline MGPT even when tumor testing is performed 2.
In populations with known founder mutations (e.g., Ashkenazi Jewish BRCA1/2 founders), consider founder-specific testing first, then proceed to full panel if negative and clinical suspicion persists 7.