Background: The role of gefitinib for the treatment of advanced non-small cell lung cancer (NSCLC) is evolving. We undertook a systematic review to evaluate the available evidence from all randomised trials.

Objectives: To determine the effectiveness and safety of gefitinib as first-line, second-line or maintenance treatment for advanced NSCLC.

Search methods: We performed searches in CENTRAL, MEDLINE and Embase from inception to 17 February 2017. We handsearched relevant conference proceedings, clinical trial registries and references lists of retrieved articles.

Selection criteria: We included trials assessing gefitinib, alone or in combination with other treatment, compared to placebo or other treatments in the first- or successive-line treatment of patients with NSCLC, excluding compassionate use.

Data collection and analysis: We used the standard Cochrane methodology. Two authors independently assessed the search results to select those with sound methodological quality. We carried out all analyses on an intention-to-treat basis. We recorded the following outcome data: overall survival, progression-free survival, toxicity, tumour response and quality of life. We also collected data for the following subgroups: Asian ethnicity and positive epidermal growth factor receptor (EGFR) mutation.

Main results: We included 35 eligible randomised controlled trials (RCTs), which examined 12,089 patients.