A new analysis of trial data for gefitinib indicates it is most likely to benefit patients with non-small cell lung cancer who have never smoked, have bronchioloalveolar cell carcinoma, or are female, according to an article in the March 15th issue of the Journal of Clinical Oncology.

Gefitinib, which blocks molecular signals generated by binding of surface epidermal growth factor receptor, recently gained approval for use in the USA for patients with advanced non-small cell lung cancer.

Investigators believe that research into the basis for correlations between lack of tobacco use, bronchioloalveolar cell carcinoma, and female gender may help explain why the agent shrank tumors in only ten percent of trial patients, although the enzyme activated by receptor binding (tyrosine kinase) is believed to be present and activated in most patients with non-small cell lung cancer.

Results from additional research could help physicians select those patients who will most benefit from the drug and also provide information that could lead to development of a molecular screen to grade expression and over-expression of the gene for the enzyme activated by binding of the growth factor receptor.

“We saw a wide range of patient sensitivity and benefit with gefitinib during our trials and we wanted to understand why,” said Vincent Miller, MD, the current study’s lead author. “It seemed clear that there must be a biological difference between the patients who responded to the compound and those who did not. Having some clinical features to refine decision making while we try to develop a more definitive molecular fingerprint, is of prime importance for our patients.”

In the current work, Miller and his American colleagues reviewed data for139 patients with non-small cell lung cancer who participated in three separate clinical trials of gefitinib at their cancer center. They found that 21 patients, or 15 percent, experienced partial responses per radiography. Categorization and comparison of patients by smoking history, histologic disease type, and gender revealed which factors predicted positive response to therapy.

“In this single center study, the clinical, pathologic, and radiologic assessments were more consistent and uniform, allowing us to revisit data in a manner that would not be possible in a multi-center trial,” explained Robert Heelan, MD, a radiologist and senior author of the study.

Mark Kris, MD, lead investigator of the Phase II, multi-center trial of gefitinib, said the analysis will encourage future study of factors that define the molecular characteristics of non-small cell lung cancer. “This raises the hope that this disease can be fought even more effectively,” said Kris.