Those findings come from a Boston-based team, reporting in the October 28 online issue of Clinical Cancer Research. Dr. Bruce E. Johnson with the Dana-Farber Cancer Institute and colleagues note that CNS involvement is a frequent occurrence in patients with NSCLC. Gefitinib and erlotinib can penetrate into the CNS, but their impact on the development and control of CNS metastases is unclear.
Reviewing their 6-year experience with routine EGFR characterization in lung cancer patients, the researchers identified 100 patients with stage IIIB/IV NSCLC and somatic EGFR mutations who were treated with gefitinib or erlotinib.
“Eighty-four patients have progressed after a median potential follow-up of 42.2 months,” the team reports. “The median overall survival for the entire cohort was 33.1 months.”
The median time to progression was 13.1 months, and 28 patients developed CNS progression — 8 of whom had previously treated brain metastases, according to the report.
Dr. Johnson and colleagues calculate that the actuarial risks of CNS progression at 1 year and 2 years were 7% and 19% respectively. That compares with historical rates of CNS failure of 40-55% following definitive therapy of stage III NSCLC.
Nonetheless, the authors conclude, “Further research is needed to distinguish between the underlying rates of developing CNS metastases between NSCLC with and without EGFR mutations and the impact of gefitinib and erlotinib versus chemotherapy on CNS failure patterns in these patients.”