Clinical

WASHINGTON – An assay that can detect the presence of epidermal growth factor receptor mutations in non–small cell lung cancer patients is being vastly underused in the United States, according to a study presented at the conference sponsored by the American Association for Cancer Research.

An EGFR diagnostic was launched by Genzyme Corp. in 2005. Patients with EGFR mutations generally respond better to certain therapies – such as erlotinib (Tarceva) and geftinib (Iressa) – that target these mutations.

Earlier this year, the American Society of Clinical Oncology (ASCO) and the National Comprehensive Cancer Network (NCCN) recommended EGFR testing for lung cancer patients. ASCO’s provisional clinical opinion advocated that patients with advanced NSCLC who were being considered for treatment with a tyrosine kinase inhibitor should be tested for EGFR mutations. The NCCN called for EGFR testing after histologic diagnosis of adenocarcinoma, large cell carcinoma, or undifferentiated carcinoma, but not in patients with squamous cell disease which is less likely to be EGFR positive.

And yet, it appears that the assay is not being widely used, said Julie Lynch, R.N., a research assistant at the University of Massachusetts, Boston, who conducted the study.

After conducting a systematic review of erlotinib trials, Ms. Lynch, a PhD nursing candidate, was concerned that few blacks or Hispanics were enrolled. She decided to determine whether minorities might not be included because they were not being tested for the EGFR mutations.

Genzyme agreed to share the data it had with Ms. Lynch. The Genzyme database represents an estimated 98% of community hospital use of the EGFR assay. However, it does not present a comprehensive picture. Ms. Lynch had very little data from the 59 cancer centers with special designation from the National Cancer Institute. Many of these NCI centers have separate licenses from Genzyme or conduct their own assays for research purposes.

To get a better picture of where these tests were being used, she merged Genzyme’s data on EGFR testing with six public data sets, from the U.S. Census Bureau, the Centers for Disease Control and Prevention, the National Institute of Standards and Technology, the Centers for Medicare and Medicaid Services, and the NCI. She linked test orders to specific providers to create a nationwide map that shows county-by-county use of EGFR testing.

Ms. Lynch found that in 2010, some 6,056 tests were ordered by acute care hospitals, 93 by federal hospitals (primarily Veterans Affairs hospitals), 527 by pathology labs, and 258 by independent outpatient oncology clinics or physicians. She was able to ascertain that some 1,019 EGFR tests were ordered by NCI centers, but again, this is likely only a partial tally.

To put these numbers in perspective, the American Cancer Society estimates that there will be about 221,130 new cases diagnosed in 2011 for all types of lung cancer combined. Non–small cell lung cancers account for 80%-90% of all lung cancers.

Test orders seemed to be clustered around NCI-designated centers, Ms. Lynch said in an interview. Most likely, community hospitals that were within a relatively close distance to those NCI centers ordered more EGFR tests to compete.

10/04/11  

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FROM A CONFERENCE SPONSORED BY THE AMERICAN ASSOCIATION FOR CANCER RESEARCH

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Vitals

Major Finding: Only about 8,000 orders for EGFR assays could be verified in 2010.

Data Source: A nationwide map based on a Genzyme company database and six public data sets.

Disclosures: The study was funded by grants from the U.S. Department of Education and the National Institutes of Health, and was aided by the provision of data by Genzyme Genetics. Ms. Lynch is a former employee of Genentech.