This is a multi-center retrospective observational research study collecting data for participants initiated on docetaxel for the treatment of relapsed non-small cell lung cancer (NSCLC) up to 6 years before start of data collection and who have completed/stopped docetaxel treatment at least 30 days prior to data collection. The primary goal of this study is to describe the percentage of participants with at least one neutropenic sepsis (NS) episode following initiation of treatment with single-agent docetaxel. Data will be collected until end of docetaxel treatment plus an additional 30 days to allow for presentation with toxicity.

Inclusion Criteria:

• Diagnosed with locally advanced or metastatic (stage Ill or IV) non-small cell lung cancer (NSCLC)
• Relapsed disease following, or unable to tolerate, at least one line of prior chemotherapy
• Initiated on single-agent docetaxel up to a maximum of 6 years prior to date of collection
• Aged 18 years at date of first docetaxel dose
• Completed or stopped treatment with docetaxel at least 30 days prior to date of data collection

Exclusion Criteria:

• Receiving docetaxel in an interventional clinical trial
• For whom no details of absolute neutrophil count are recorded

Participants initiated on docetaxel for the treatment of relapsed non-small cell lung cancer (NSCLC)