title: Lung cancer chemoprevention: difficulties, promise and potential agents?
abstract: BACKGROUND
  In a variety of cancers there is evidence that specific regimens can prevent or significantly delay the development of cancer. Thus, for breast cancer (ER+) use of SERMs or aromatase inhibitors can substantially decrease tumor incidence. For cervical cancer, HPV vaccination will inhibit long term cancer incidence. For colon cancer, the second greatest cancer killer, administration of aspirin and other NSAIDs decreases advanced colon adenomas in Phase II trials and epidemiologic data support their ability to prevent colon cancer. To date prevention trials in the area of lung cancer have shown minimal efficacy.
  
  
  METHODS
  The paper examines and discusses in greater detail certain promising agents which the authors have tested either preclinically and or in early phase clinical trials. These agents include RXR agonists, EGFr inhibitors, NSAIDs and Triterpenoids. Other agents including glucocorticoids, pioglitazone and iloprost are briefly mentioned. In addition, the paper presents various types of potential Phase II lung cancer prevention trials and describes their strengths and weaknesses. The potential use of various biomarkers as endpoints in trials e.g. histopathology, non-specific biomarkers (e.g., Ki67, cyclin D expression, apoptosis) and molecular biomarkers (e.g. specific phosphorylated proteins, gene expression etc.) is presented. Finally, we examine at least one approach, the use of aerosols, which may diminish the systemic toxicity associated with certain of these agents.
  
  
  CONCLUSIONS
  The manuscript presents: a) a number of promising agents which appear applicable to further Phase II prevention trials; b) approaches to defining potential preventive agents as well; c) approaches which might mitigate the side effects associated with potential agents most specifically the use of aerosols. Finally, we discuss biomarker studies both preclinical and clinical which might help support potential Phase II trials. The particular appeal to the preclinical studies is that they can be followed to a tumor endpoint. We hope that this will give the reader further background and allow one to appreciate the potential and some of the hurdles associated with lung cancer chemoprevention.
authors.affiliation: Hitchcock Cancer Center, Dartmoth Medical School, Lebanon, NH, USA.
authors.forename: Konstantine
authors.initials: K
authors.lastname: Dragnev
authors.forename: Ming
authors.initials: M
authors.lastname: You
authors.forename: Yian
authors.initials: Y
authors.lastname: Wang
authors.forename: Ronald
authors.initials: R
authors.lastname: Lubet
mesh_terms: D000818:Animals; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use*; D052246:Cyclooxygenase 2 Inhibitors / Q000627:therapeutic use; D006801:Humans; D008175:Lung Neoplasms / Q000517:prevention & control*; D014315:Triterpenes / Q000627:therapeutic use
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000970:Antineoplastic Agents; D052246:Cyclooxygenase 2 Inhibitors; D014315:Triterpenes