The purpose of this research study is to:

• see if gefitinib pills can shrink Stage 1 or 2 non-small cell lung cancers before surgery
• see if your non-small cell lung cancer has a mutation in a certain part of the EGFR gene
• see if patients whose tumor does shrink with gefitinib treatment are more likely to have a mutation in a certain part of the EGFR gene
• see if the pattern of protein expression in the blood is related to the tumor's sensitivity or resistance to gefitinib treatment.
• see if expression of certain genes in the tumor are related to the tumor's sensitivity or resistance to gefitinib treatment.

This is a phase II, single institution trial to correlate gefitinib response and mutations in the protein-tyrosine kinase domain of the EGF receptor gene. The study will be conducted in patients with Stage I and II NSCLC who have been determined to be operable and resectable.

Patients must have 1 or more of the following features: never smoker or smoking history of < 15 pack years and/or features of bronchioloalveolar lung cancer. 50 patients will be enrolled on this study. Treatment will be with gefitinib for at least 21 days before surgery (depending on the timing of the surgery). Patients will discontinue gefitinib 2 days before their operation. For patients that demonstrate a radiographic response to gefitinib preoperatively and /or patients with mutations in the protein-tyrosine kinase domain of the EGF receptor gene (identified from the surgical sample), gefitinib will continue for 2 years post-surgery. Patients who do not have evidence of radiographic response or mutations in the protein-tyrosine kinase domain of the EGF receptor gene will be removed from the study.

Inclusion Criteria:

• Pathologic confirmation of malignancy at Memorial Sloan-Kettering
• Patients must have previously untreated stage I or II NSCLC (T11-2N0M0, T1-2N1M0, T3N0M0) and 1 of the following features: never smoker or < 15 pack year smoking history and/or bronchioloalveolar cancer (either pure BAC, BAC with focal invasion or adenocarcinoma with BAC features)
• Patients must have been determined to be operable and resectable by the treating thoracic surgeon.
• Age >18 years.
• Measurable indicator lesions
• Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

• Pregnant or lactating women or women of childbearing potential not using effective contraception. Men participating in the trial must also use effective contraception when sexually active.
• Patients may not be receiving any other investigational agents.
• Any history of or evidence of interstitial lung disease (patients with chronic stable radiographic changes who are asymptomatic need not be excluded).