Therapeutic efficacy of gefitinib and erlotinib in patients with advanced lung adenosquamous carcinoma.

BACKGROUND

Adenosquamous carcinoma (ASC) of the lung is a rare subtype of nonsmall-cell lung cancer (NSCLC). To date, the efficacious targeted therapy for advanced ASC remains unclear and the epidermal growth factor receptor (EGFR) mutation rate is not well known.

METHODS

We retrospectively reviewed clinical information of patients with ASC who were treated with gefitinib or erlotinib at Zhejiang Cancer Hospital between January 2007 and December 2011. Survival analysis was evaluated by the Kaplan-Meier method. EGFR mutations were assessed in part using direct sequencing methods.

RESULTS

In total, 49 patients with a median age of 57 years were used in this study. Thirteen patients achieved a partial response and 19 had disease stabilization. The objective response rate was 26.5%, and the disease control rate was 65.3%. The median progression-free survival and overall survival were 4.3 and 17.6 months, respectively. In 21 patients with adequate specimens for molecular analysis, 7 (33.3%) had EGFR mutations (4 with deletions within exon 19 and 3 with L858R messenger mutation in exon 21). EGFR mutations were significantly more frequent in women (4/9, 44.4%) than men (3/12, 25%), never-smokers (6/15, 40%), and smokers (1/6, 16.7%).

CONCLUSION

EGFR-tyrosine kinase inhibitor (TKI) is an effective treatment for ASC. The frequency of EGFR mutation and clinical characteristics of the EGFR mutants in ASC are similar to those of Asian patients with adenocarcinoma.