Whole Genome Sequencing Advances Diagnosis and Treatment for Cancers of Unknown Primary
Archynewsy.com – March 20, 2026 – For patients facing metastatic cancers of unknown primary (CUP), where the original source of the cancer remains unidentified despite standard diagnostic procedures, new advancements in genomic sequencing are offering hope. Whole genome sequencing (WGS) is demonstrating superior diagnostic capabilities and broadening treatment options compared to traditional panel testing.
Currently, individuals with CUP often encounter barriers to accessing targeted therapies and clinical trials. However, the application of WGS is changing this landscape. Studies reveal that WGS detects all reportable DNA features identified by panel testing – which typically analyzes 386-523 genes – and additionally identifies further mutations relevant to diagnosis or treatment in 76% of cases.
A recent study highlighted the ability of WGS, combined with a specialized prediction algorithm called CUPPA, to determine the tissue of origin in 71% of CUP cases that remained undiagnosed through conventional clinicopathological review. WGS informs treatment strategies for 79% of patients, a significant increase from the 59% achieved with panel testing.
The benefits of WGS extend to the analysis of circulating tumor DNA (cfDNA). In patients with a high cfDNA tumor fraction (over 7%), WGS enables high-likelihood CUPPA predictions in 41% of cases. This is particularly impactful as it allows for analysis using routine pathology samples and cfDNA.
In the Netherlands, WGS is now reimbursed within the diagnostic process for CUP patients, signifying growing recognition of its value. Research indicates that WGS can determine the primary tumor type in 68% of CUP patients, and identify actionable genetic events for targeted therapy in 47% of patients. A WGS-based prediction algorithm has demonstrated 78% accuracy in predicting tumor type in independent validation studies.
These advancements represent a significant step forward in the diagnosis and treatment of cancers of unknown primary, offering renewed hope for patients and paving the way for more personalized and effective cancer care.
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