By Dr Lauren Dixon, NLCA Clinical Fellow, on behalf of the NLCA Project Team
Recent data on people diagnosed with lung cancer in 2024 from Wales provide an early snapshot of how genomic testing is being recorded. The dataset is relatively small and still evolving, but it offers a useful starting point for understanding current practice.
The National Lung Cancer Audit (NLCA) described the care of 2,135 people who were diagnosed with lung cancer in Wales during 2024 in its 2026 State of the Nation report. A subset of 1,546 patients had records available from the new Welsh cancer data collection system; this includes fields for information about whether or not a patient had a genomic test. The 2024 dataset contained 745 patients (48%) that had at least one recorded genomic test result related to four biomarkers commonly used to guide treatment decisions in non-small cell lung cancer (NSCLC): PD-L1 expression, EGFR mutations, ALK fusions, and ROS1 fusions.
As expected, genomic testing was recorded predominantly in people with confirmed NSCLC. Among these, 710 patients had at least one genomic test recorded. Only a small number of results were recorded among patients with small cell lung cancer, carcinoid tumours or unconfirmed histology.
What do the results show?
Starting with the tests for PD-L1 expression, the results were broadly consistent across the health boards. Among patients with recorded results, around one quarter had high PD-L1 expression (>50%), with roughly half having expression <1%. This pattern aligns with what would be expected in a contemporary NSCLC population.
Results for ALK and ROS1 fusions were in keeping with the known epidemiology for NSCLC. Positive results were rare across all health boards, and overall prevalence was around 1-2%.
In contrast, there was marked variation between health boards in the EGFR results. In some areas, a high proportion of patients were recorded as having “resistance mutations”, while other boards reported predominantly wild-type EGFR. Given that resistance mutations are uncommon at diagnosis, especially in unselected populations, this pattern most likely reflects differences in data coding, test interpretation, or the way results have been mapped into the new data system. This reinforces the importance of clinical validation and standardisation as the cancer data system matures.
Looking ahead
These early data on genomic testing in Wales provide a baseline description of an area of care that is evolving. The introduction of the new cancer informatics system that allows data on genomic testing to be captured is a major benefit, and some teething troubles might be expected during its implementation. We expect data quality to improve.
We anticipate future analyses will be able to link the testing results with information on the use of target therapies and immunotherapies. This will enable the uptake of precision medicine to be monitored, helping clinicians, services and policymakers understand how genomic testing supports the care of people diagnosed with lung cancer in Wales.
