An Observational Study of Tarceva (Erlotinib) in Previously Treated Patients With Advanced Non-Small Cell Lung Cancer With Wild-Type Epidermal Growth Factor Receptor (EGFR) Gene (WILT)

Inclusion Criteria: * Adult patients, \>/= 18 years of age * Histologically or cytologically confirmed locally advanced or metastatic non-small cell lung cancer (NSCLC) * Patients with known wild-type EGFR gene; patients with unknown EGFR mutation status are allowed if they fulfil the following criteria: * squamous cell carcinoma lung cancer histology, and * current smoker, or former smoker who has stopped smoking less than 10 years ago and has had a total of \>15 pack-years of smoking * Eastern Cooperative Oncology Group (ECOG) performance status 0 to 2 * Patients having failed one prior chemotherapy regimen and eligible for a second-line treatment with Tarceva Exclusion Criteria: * Current treatment with an investigational drug or participation in another investigational study * Severe or uncontrolled systemic disease, active infection, concomitant malignancy or a second primary malignancy except for in situ carcinoma of the cervix or adequately treated basal cell carcinoma of the skin * Clinically active interstitial lung disease * Recent myocardial infarction or unstable angina * Progressive or uncontrolled brain metastases