This observational study will evaluate the efficacy and safety of Tarceva (erlotinib) in second line in patients with locally advanced or metastatic squamous non-small cell lung cancer (NSCLC) after failure of first line platinum-based chemotherapy. Eligible patients will be followed for 12 months.

Inclusion Criteria:

• Adult patients, >/= 18 years of age
• Histologically or cytologically confirmed advanced (Stage IIIB) or metastatic (Stage IV) squamous non-small cell lung cancer after failure of first-line platinum-based chemotherapy
• Patients for whom the treating physician has decided to initiate treatment with Tarceva

Exclusion Criteria:

• Mixed non-small cell and small-cell lung carcinoma or mixed squamous cell carcinoma with predominant adenocarcinoma component
• Current participation in a clinical trial evaluating an anticancer treatment

Patients with locally advanced or metastatic squamous NSCLC initiating 2nd line treatment with Tarceva