A study published Online First in The Lancet Oncology reveals that patients who suffer from the most common form of lung cancer and whose tumors express high levels of epidermal growth factor receptor (EGFR) tend to benefit more from being treated with cetuximab and have a longer life-expectancy compared with those given chemotherapy alone.

According to the findings, testing for level of EGFR expression could be applied in everyday clinical practice to predict which non-small-cell lung cancer (NSCLC) patients are most likely to respond to cetuximab plus chemotherapy treatment in order to have a higher advantage of surviving.

Lead author Robert Pirker from the Medical University of Vienna in Vienna, Austria explains:

“EGFR expression level is the first biomarker shown to be associated with survival benefit of a targeted therapy added to first-line chemotherapy in patients with advanced NSCLC.”

At the moment, there are few treatment options for those suffering from advanced NSCLC and their life expectancy is short, meaning strategies to establish which patients are most likely to benefit from new targeted drugs are urgently required. Until now, the EGFR status remains to be one of the most promising predictive pretreatment biomarkers.

According to the 2009 First-Line Erbitux in Lung Cancer (FLEX) randomized trial, adding cetuximab to standard chemotherapy as a first-line treatment demonstrated a significantly improved survival in NSCLC patients.

In this new study researchers re-analyzed the FLEX study data to evaluate whether the level of expression of EGFR was linked to response to cetuximab.

1,121 of 1,125 patients of the researchers study population had tumor EGFR expression data and were included in the analysis. By using a scoring system that ranged from 0-300 researchers were able to identify those with high and low levels of the EGFR protein. They defined low levels of EGFR as scoring less than 200, whilst high levels were defined as a score of 200 and above.

Their findings revealed an overall survival benefit from cetuximab without an increase in toxic side effects in patients with high EGFR expression. Patients who received cetuximab plus chemotherapy survived on average 1 year following treatment with 24% surviving at 2 years whilst those who only received chemotherapy alone survived for an average of 9.6 months with 15% surviving at 2 years.

The researchers noted no difference in overall survival between the two groups in patients with low (scoring less than 200) EGFR expression.

In the high EGFR expression group researchers established an overall survival benefit in all major NSCLC histological subgroups, including the two most common forms of cancers, namely squamous-cell carcinoma and adenocarcinoma.

In their concluding statement the researchers say:

“We believe that high EGFR expression might now be applied clinically as a predictive biomarker to identify patients with advanced NSCLC who will benefit from the addition of cetuximab to first-line chemotherapy.”

Fred Hirsch from the University of Colorado Cancer Center in Colorado, USA, and Roy Herbst from the Smilow Cancer Hospital in New Haven, USA, say in a linked comment:

“Clearly, the use of targeted drugs requires specific criteria for patient selection based on the assessment of a molecular target… Use of EGFR immunohistochemistry in the FLEX study seems to be an encouraging step towards personalized medicine for patient subgroups with advanced lung cancer who will potentially receive cetuximab.”

Written by Petra Rattue