NEW YORK (Reuters Health) – Patients with advanced squamous lung cancer may respond favorably to erlotinib even if they don’t harbor epidermal growth factor receptor (EGFR) mutations, Taiwanese researchers have found.
As Dr. Gee-Chen Chang told Reuters Health by email, “A significant proportion of squamous lung cancer patients would benefit from erlotinib treatment, despite the low EGFR mutation rate. It might target additional pathways other than the EGFR mutations.”
The new findings were published online March 15 in Lung Cancer.
Dr. Chang of National Yang-Ming University in Taipei and colleagues reviewed data on 92 patients with inoperable disease given erlotinib orally. None had received other EGFR-tyrosine kinase inhibitors (TKIs) or other concurrent treatment.
Sixteen patients achieved partial response and nine had stable disease, for an overall response rate of 17.4%. This, say the investigators, was “much higher” than the EGFR mutation rates. Of the 27 patients tested, only two (7.4%) had EGFR complex mutations. One of these patients responded and the other did not.
“The sensitivity of EGFR mutation tests has been suspected to be one of the possible reasons for the responses to EGFR-TKIs in patients without detectable EGFR mutations,” the researchers write. Another possibility is that the drug might target other pathways.
In all, the disease-control rate was 27.2%. In patients whose disease was controlled, progression-free survival was 7.8 months and overall survival was 20.7 months. In those without disease control the corresponding periods were 1.3 and 2.7 months, respectively.
The results appear promising but given the limitations of retrospective studies, the researchers call for prospective studies “to verify the efficacy of erlotinib in lung squamous cell carcinoma patients and to define the underlying mechanisms.”
Lung Cancer 2012.