EGFR mutation testing practices within the Asia Pacific region: results of a multicenter diagnostic survey

Abstract

Introduction: The efficacy of epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in EGFR mutation-positive non-small-cell lung cancer (NSCLC) patients necessitates accurate, timely testing. Although EGFR mutation testing has been adopted by many laboratories in Asia, data are lacking on the proportion of NSCLC patients tested in each country, and the most commonly used testing methods.

Methods: A retrospective survey of records from NSCLC patients tested for EGFR mutations during 2011 was conducted in 11 Asian Pacific countries at 40 sites that routinely performed EGFR mutation testing during that period. Patient records were used to complete an online questionnaire at each site.

Results: Of the 22,193 NSCLC patient records surveyed, 31.8% (95% confidence interval: 31.2%-32.5%) were tested for EGFR mutations. The rate of EGFR mutation positivity was 39.6% among the 10,687 cases tested. The majority of samples were biopsy and/or cytology samples (71.4%). DNA sequencing was the most commonly used testing method accounting for 40% and 32.5% of tissue and cytology samples, respectively. A pathology report was available only to 60.0% of the sites, and 47.5% were not members of a Quality Assurance Scheme.

Conclusions: In 2011, EGFR mutation testing practices varied widely across Asia. These data provide a reference platform from which to improve the molecular diagnosis of NSCLC, and EGFR mutation testing in particular, in Asia.

FIGURE 1.

Nature of samples tested for EGFR mutations at participating sites. No data were available for Malaysia. †Data from responses to question: “(Amongst NSCLC cases tested for EGFR mutations in your laboratory, what is the) number of surgical specimen samples tested?” ‡Data from responses to question: “(Amongst NSCLC cases tested for EGFR mutations in your laboratory, what is the) number of biopsy and/or cytology samples tested?” §Data from responses to question: “How many samples tested for EGFR mutation during 2011 were cytology samples?” Proportions of biopsy and/or cytology samples and of surgical specimens were calculated using data from only those sites that provided answers to both questions on “NSCLC samples that were biopsy and/or cytology samples” and “NSCLC samples that were surgical specimens.” The proportions of cytology samples were calculated using data from the sites that provided answers to all three questions, i.e., on “NSCLC samples that were biopsy and/or cytology samples,” “NSCLC samples that were surgical specimens” and “NSCLC samples that were cytology samples.” EGFR, epidermal growth factor receptor; NSCLC, non–small-cell lung cancer.

FIGURE 2.

Most commonly used EGFR mutation testing methods for tissue and cytology samples across Asia, determined as a percentage of participating sites. Cobas EGFR Mutation Test (Roche) was included in the survey as an option, but was not selected by any site as the most commonly used test. †Two sites (5.0%) had missing data or did not test cytology samples. ‡Nature of methods not ascertained. EGFR, epidermal growth factor receptor.

FIGURE 3.

Information about EGFR mutation testing sites that participated in the survey. A, Type of laboratory; B, accreditation; and C, participation in QA schemes amongst participating laboratories. EGFR, epidermal growth factor receptor; QA, quality assurance.