EGFR mutation testing trends for patients with metastatic, non-squamous non-small cell lung cancer (non-SQ NSCLC) in Queensland, Australia from 2014-2021.

Abstract

e13505 Background: Lung cancer is the leading cause of cancer-related mortality worldwide. Epidermal growth factor receptor (EGFR) is the most common actionable mutation in non-small cell lung cancer (NSCLC) with routine testing recommended globally. In late 2013, screening for EGFR mutations was publicly funded in Australia for metastatic non-SQ-NSCLC. However, timely EGFR results are not universally available, often limited by tissue quantity/quality or prolonged turnaround times. This in turn affects access to treatment and thus survival. Methods: We aimed to examine the rates of EGFR testing over time and explore factors impacting results. Cases were identified from the Queensland Oncology Repository, a clinical database consolidating diagnostic, treatment and outcome data for all Queenslanders with cancer through the Queensland Cancer Registry. Cases were included if they had metastatic non-SQ-NSCLC, EGFR testing available via Pathology Queensland, and no other metastatic solid organ cancer within 1 year. Primary outcomes were EGFR mutation testing rates and time from first biopsy to EGFR mutation result, stratified by year of diagnosis and rurality. Results: A total of 3369 cases were included, of which 2871 had EGFR testing. The EGFR mutant (mt) rate was 12.6%, while 16.1% of cases had no EGFR results. Of cases without a conclusive EGFR result, reasons included: 179 transitioned to best supportive care before testing, 208 with insufficient tissue for a conclusive result, and 155 without testing for unclear reasons. The average time from biopsy to EGFR result improved from 29.9 days in 2014 to 21.5 days in 2021, with no significant difference in time to result between major cities, regional or remote areas. Cases with no EGFR results were more prevalent in rural areas. The proportion of patients living in outer regional/remote areas with no EGFR result was 21.1% compared to 15.5% in those living in major cities/inner regional sites. This was a relative increase of 36.2% (95% CI: 10.1% - 68.6%), a significant result (χ2 = 7.7483, p=0.005). Cases with no EGFR results in outer regional and remote sites declined from 30.1% in 2014-2015 to 15.3% in 2020-2021. Conclusions: EGFR mutation testing and result time has improved since 2014. Though time to result was not affected by rurality, significantly more rural patients lacked conclusive EGFR data, highlighting a gap in access to care. The cumulative EGFR no result rate of 16% and result time of 24 days indicates health systems need to more rapidly adapt to new treatment paradigms, particularly in the era of targeted therapies. [Table: see text]