Inhaled insulin for the early detection of lung cancer.

Early lung cancer detection may save lives but is controversial [1]. Recently a study appeared documenting improved survival of early lung cancer detected with spiral CT [2]. Biochemical methods of early lung cancer detection have been developed. For example, measurement of an autoantibody response to one or more tumor-associated antigens in an optimized panel assay provides a sensitive and specific blood test to aid the early detection of lung cancer [3]. Early lung cancer can also be detected by obtaining fluid and tissue samples. Respiratory tract material, including sputum or bronchial fluid or other pulmonary tissue or thoracic cells or regional lymph nodes, is assayed with monoclonal antibodies for antigens whose enhanced presence correlates with the development of lung cancer [4]. Surface enhanced laser desorption/ionization (SELDI) mass spectrometry has been used to identify five distinct potential lung cancer serum biomarkers with high sensitivity and specificity [5]. Very small malignant lung tumors might be detected by allowing the subject to inhale powdered insulin, preceded and followed by measurement of circulating hormones, growth factors, and receptor proteins in the blood, particularly those that lung tumors are known to produce: