Proteomics as a Method for Early Detection of Cancer A Review of Proteomics, Exhaled Breath Condensa.pdf

Proteomics as a Method for Early Detection of Cancer: A Review of Proteomics, Exhaled Breath Condensate, and Lung Cancer Screening Dean H. Conrad1, Jesse Goyette1, and Paul S. Thomas1,2 1Inflammatory Diseases Research Unit, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia; 2Department of Respiratory Medicine, Prince of Wales Hospital, Randwick, Sydney, NSW, Australia. The study of expressed proteins in neoplasia is under- going a revolution with the advent of proteomic analy- sis. Unlike genomic studies where individual changes may have no functional significance, protein expression is closely aligned with cellular activity. This perspective will review proteomics as a method of detecting markers of neoplasia with a particular emphasis on lung cancer and the potential to sample the lung by exhaled breath condensate (EBC). EBC collection is a simple, new, and noninvasive technique, which allows sampling of lower respiratory tract fluid. EBC enables the study of a wide variety of biological markers from low molecular weight mediators to macromolecules, such as proteins, in a range of pulmonary diseases. EBC may be applied to the detection of lung cancer where it could be a tool in early diagnosis. This perspective will explore the poten- tial of applying proteomics to the EBC from lung cancer patients as an example of detecting potential biomar- kers of disease and progression. KEY WORDS: exhaled breath condensate; proteomics; lung cancer; screening tests. J Gen Intern Med 23(Suppl 1):78–84 DOI: 10.1007/s11606-007-0411-1 ? Society of General Internal Medicine 2007 BACKGROUND Neoplasia is one of the major causes of premature morbidity and mortality in the developed world, accounting for up to 12% of all deaths.1 Early detection is vital for the effective treatment of many neoplasms, providing evidence to substantiate the implementation of population-wide screening programs in the hope of reducing the mortality and m