EGFR Testing Not Done in 25% of Lung Cancer Patients

Liam Davenport

April 17, 2015

Many patients with advanced non-small cell lung cancer (NSCLC) are missing out on a crucial genetic test to determine whether they would benefit from more targeted therapy, new research suggests.

A survey of more than 550 oncologists around the world revealed that EGFR genetic testing is not being conducted in about 25% of patients with NSCLC. And even when the test is requested, treatment is started before the results are back in one-quarter of cases.

The research was presented at the 2015 European Lung Cancer Conference in Geneva.

Guidelines from the International Association for the Study of Lung Cancer (IASLC) recommend that all patients diagnosed with advanced NSCLC, except those with squamous cell carcinoma, undergo EGFR testing, and that the results be used to guide treatment decisions.

Recent research has indicated that matching EGFR mutation status to specific tyrosine kinase treatments can improve overall survival.

However, the IASLC guidelines are not being followed in a number of cases, said lead researcher James Spicer, MD, PhD, reader in experimental oncology at King's College London at Guy's Hospital in the United Kingdom.

"Not only were some suitable patients not tested at all for tumor EGFR mutations, some patients did undergo testing but the treatment decision about whether to give an EGFR inhibitor or chemotherapy as first-line treatment was taken without reference to the result," he said in a statement.

A representative sample of 562 oncologists from Canada, France, Germany, Italy, Japan, South Korea, Spain, Taiwan, the United Kingdom, and the United States completed an online survey from December 2014 to January 2015.

The survey assessed the prevalence of mutation testing, attitudes and barriers to testing, and the way the results affect the choice of therapy for patients with advanced NSCLC.

Dr Spicer and colleagues found that EGFR testing was requested before the administration of first-line therapy for 81% of patients with stage IIIb/IV NSCLC. The most common reason for not ordering a test was that the patient had the wrong type of histology.

"Most centers, especially the big academic centers, know enough about those patients not to waste resources on testing for a mutation that they are very unlikely to find," Dr Spicer explained.

"Sure enough, the most likely reason that our respondents cited for not testing was that patients have the wrong type of tumor to have a mutation...and that's fine," he told Medscape Medical News.

The next most common reason was a lack of diagnostic material. The tumor is difficult to access, so "by the time we've decided that it's a lung cancer in the pathology lab, there isn't enough cellular material left to extract the DNA and do this sort of genetic testing," he pointed out.

"But that should be less and less of a problem in the modern era, because we getting better at obtaining biopsies with newer techniques, and we're getting better at doing the test with more sensitive genetic tests," he added.

The survey revealed a number of other reasons for not ordering EGFR testing, which Dr Spicer described as "a bit more worrisome." These included cases in which a patient was deemed unfit to undergo testing.

Not testing someone who is wheelchair-bound or breathless, and thereby not offering the most appropriate treatment, which could quickly improve a patient's health status, "is really not good modern oncology," he noted.

"Maybe there's an area of education around prescribers that still needs to be done," he added.

Two other reasons cited for not offering EGFR testing — patients were smokers or were too old — go against the guidelines. Many smokers do undergo EGFR mutation, and elderly patients can tolerate, and might benefit from, tyrosine kinase therapy, Dr Spicer noted.

Finally, a major reason cited for not ordering EGFR testing was the long turnaround time. Dr Spicer said he can "sympathize"; the turnaround time is weeks at some centers.

For patients who underwent testing, the oncologist received the results before first-line therapy was initiated in 77% of cases (ranging from 51% in France to 89% Japan). In 23% of cases, first-line therapy was initiated before the test results were available.

"It's a bit paradoxical," Dr Spicer said, "to go to the trouble of doing the test and starting the patient on treatment before the mutation test is back."

"Because these targeted drugs are only licensed by the regulators in the presence of a mutation, if you're starting before the mutation result is back, then it's presumably not the targeted drug that you're starting them on," he said.

Respondents reported initiating therapy before EGFR results were available because the test took too long or because the patient wanted to start therapy immediately.

According to the survey, 23% of oncologists do not consider EGFR mutation subtypes when making their treatment decisions, but 49% do.

When choosing a first-line therapy for NSCLC patients, a clinically relevant increase in overall survival was cited by 75% of oncologists.

"Overall, it looks like people are getting it right," Dr Spicer said. However, "there are some significant areas where we could, perhaps, improve things by offering more patients the test and then doing more with that result."

The survey was conducted by Kantar Health and funded by Boehringer Ingelheim. Dr Spicer reports receiving payments not exceeding the cost of research for clinical trials funded by Boehringer Ingelheim, and receiving speaker fees from and serving on advisory boards for the company. Coauthor Matthew Peters, MD, from the Concord Repatriation General Hospital in Sydney, Australia, reports previously receiving honoraria from Boehringer Ingelheim for the development and delivery of CME in unrelated therapy areas.

2015 European Lung Cancer Conference (ELCC): Abstract LBA2_PR. Presented April 17, 2015.

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