Substantial benefits in non-small-cell lung cancer from customising eroltinib therapy

Lung cancer patients whose tumours carry specific genetic mutations can achieve significantly longer survival when treated with targeted therapies such as erlotinib, Spanish researchers report.

Investigators from the Spanish Lung Cancer Group conducted the largest-ever study to examine the benefits of customising lung cancer treatment based on mutations in the epidermal growth factor receptor (EGFR) gene.

The results, announced at the 33rd European Society for Medical Oncology congress in Stockholm, showed that patients with the mutations survived for almost two years on average when treated with erlotinib.

ìFor the first time in lung cancer management, doctors are able, by testing EGFR mutations, to identify a subgroup of patients (between 15-22% according to our experience) who can obtain a new survival landmark in advanced non-small-cell lung cancer, with oral EGFR inhibitors like erlotinib,î said lead investigator Prof. Rafael Rosell.

The group took tumour biopsies from 2,312 patients with advanced non-small-cell lung cancer and screened them for two common mutations in the gene for epidermal growth factor receptor, which can be a cause of lung cancer.

The two mutations they screened for were a deletion in exon 19 of the receptorís tyrosine kinase domain, and a mutation in exon 21. Tumours with EGFR mutations are more frequently seen in people who have never smoked and in women.

The group identified 307 patients who carried the EGFR mutations. Each was treated with erlotinib.

Based on data from 193 patients, the mean survival was 22 months, Prof. Rosell reported. For women, the mean survival was 28 months; for men, 17 months. Mean time to progression was 12 months overall, and was longer in women than in men.

The researchers saw a response to treatment in 71% of patients, including 24 patients who experienced a complete response. The probability of response was twice as high in patients aged 61-71 years and in patients with the exon 19 deletion.

ìTherefore non-small-cell lung cancers with EGFR mutations display a two-to-three-fold increment in outcome in comparison with non-small-cell lung cancers treated with chemotherapy, in which median survival is 11 months, time-to-progression is 5 months, and response 20-30%,î Prof. Rosell said.

ìThese results are a new clinical discovery. The impressive survival and response are undeniable. This is a new landmark of treatment in non-small-cell lung cancer, and the first tangible target for customizing treatment with EGFR tyrosine kinase inhibitors.î

Though the results are exciting, they only apply to non-smokers, a very small proportion of lung cancer cases.