A prospective longitudinal patient-based pilot study is proposed whereby surfaced enhanced laser desorption ionization time-of-flight mass spectroscopy (SELDI-TOF-MS) will be used to discover and validate serum proteomic expression profiles diagnostic of early lung cancer. A unique approach will be used to compare the serum proteomic expression profiles of patients with non-small cell lung cancer compared to healthy heavy smoking adults, as well as differences before and after anatomic pulmonary resection with curative intent. Discriminatory proteins will be selected by their differential expression before compared to after surgical removal of a tumor. The protein profile of blood obtained from the draining pulmonary vein at the time of resection will be used to identify materials potentially shed by the tumor that may serve as biomarkers in peripheral blood. The serum samples will be used to develop a training data set and then a test set for validation using a class prediction model. Candidate proteomic patterns will then serve as a basis for a larger prospective multi-centre clinical trial.