Question: In adult patients with advanced or metastatic non-small-cell lung cancer (NSCLC) that has become resistant to platinum-based combination chemotherapy, is there a role for single-agent docetaxel as a second-line therapy? Perspectives: Evidence was selected and reviewed by five members of the Lung Cancer Disease Site Group (DSG) of the Cancer Care Ontario Practice Guidelines Initiative and by a methodologist. The present practice guideline has been reviewed and approved by the Lung Cancer DSG, which comprises medical and radiation oncologists, pathologists, surgeons, a medical sociologist, and two community representatives. Outcomes: Survival was the primary outcome of interest. Toxicity, quality of life, and response rates were also considered. Methodology: A systematic search of the MEDLINE (1985 through September 2000), CANCERLIT (1985 through September 2000), and Cochrane Library (Issue 3, 2000) databases, and of abstracts published in the proceedings of the annual meetings of the American Society of Clinical Oncology (1993 through 2000) was conducted for evidence relevant to this practice guideline report. Results: Two randomised controlled trials (RCTs) show evidence of a benefit in overall survival and in progression-free survival when docetaxel is used as second-line treatment in patients with good performance status and advanced NSCLC resistant to platinum-based combination chemotherapy. Docetaxel at 75 mg/m2 was associated with improved survival [median: 7.5 months vs. 4.6 months; p = 0.010 (log rank)] and 1-year overall survival [37% vs. 12%; p = 0.003 (chi-square)], when compared with best supportive care. A survival advantage with this dose of docetaxel was also detected over second-line single-agent therapy with either vinorelbine or ifosfamide [1-year overall survival: 32% vs. 19%; p = 0.025 (chi-square)]. In addition, progression-free survival at 26 weeks was superior for patients receiving docetaxel 100 mg/m2 [p = 0.013 (chi-square)] and 75 mg/m2 [p = 0.031 (chi-square)] as compared with vinorelbine/ifosfamide, and progression-free survival for the two docetaxel arms pooled was significantly longer than for the vinorelbine arm or the ifosfamide arm [p = 0.005 (chi-square)]. Docetaxel at 100 mg/m2 every 3 weeks was associated with improvement in several parameters of quality of life as compared with either best supportive care or vinorelbine/ifosfamide. Recommendations: The present recommendations apply to adult patients with advanced or metastatic NSCLC that has become resistant to platinum-based combination chemotherapy. If survival is the main outcome of interest for a patient who is a candidate for second-line therapy, it is reasonable to offer docetaxel at 75 mg/m2 every 3 weeks to medically suitable patients, with a full discussion of the benefits, limitations, and toxicities. If quality of life is the main outcome of interest for a patient who is a candidate for second-line therapy, single-agent docetaxel is an option that may result in improved quality of life and reduced disease-related symptoms when compared with best supportive care. Alternative options that should be discussed with a candidate for second-line therapy include supportive care or a clinical trial involving a new agent or regimen.