EGFR Wild Type patients

EGFR mutation patients

To describe patient demographic characteristics of patients with erlotinib (single-agent) treatment duration of six months or longer, including patients who are EGFR-wt. Demographic characteristics include age, race,ethnicity, date of initial diagnosis, age at initial diagnosis, location of biopsy at diagnosis, extent of disease with description and location of metastatic sites, histology,and smoking history.

To describe patient treatment and characteristics of patients with erlotinib (single-agent) treatment duration of six months or longer, including patients who are EGFR-wt. Including number and kind of prior therapies, disease stage at initial diagnosis, sites of metastasis at time of erlotinib treatment, prior surgery, and radiation.

To describe patient outcome characteristics of patients with erlotinib (single-agent) treatment duration of six months or longer, including patients who are EGFR-wt including the reason for discontinuing erlotinib treatment, best response to erlotinib treatment and did patient receive any dose modifications while receiving erlotinib treatment.

To explore biomarker (BM) characteristics of EGFR-wt erlotinib responders.

Biopsy specimens from enrolled patient cases who are EGFR-wt will be evaluated via exploratory genetic analysis for correlated biomarkers.