Lung Cancer: Evolving Concepts

In 2008, lung cancer is projected to claim over 159,000 lives in the United States. Lung cancer remains the leading cause of cancer death in both men and women in this country, and it is the leading cause of cancer death worldwide. Over the past century, the toll from lung cancer has been enormous. In the United States we are now seeing a decrease in the lung cancer death rate in men, and a plateauing of the death rate in women. However, with over 20% of the adult American population still committed cigarette smokers, and with a substantive percentage of the population now former smokers, it is unfortunately certain that lung cancer will continue to figure prominently as a cause of morbidity and mortality into the foreseeable future. Facing this harsh reality, it is imperative that we continue to pursue a more comprehensive understanding of all facets of this disease, from epidemiology and pathogenesis to new methods of diagnostic evaluation and approaches to treatment.

This issue of Seminars in Respiratory and Critical Care Medicine addresses evolving concepts in lung cancer. Much is understood about the epidemiology of this disease, as Drs. Alberg and Nonemaker discuss in their review on population-level and individual-level risk assessment. Drs. Midthun and Jett give us an overview of the current status of lung cancer screening, outlining the controversies raised by chest computed tomographic (CT) screening studies demonstrating a higher rate of lung cancer diagnosis and longer survival with screening, but without evidence of mortality benefit. Screening studies as well as a general plethora of CT scanning have increased our awareness of the prevalence of small pulmonary nodules found on imaging studies. A comprehensive approach to the evaluations of these common radiographic findings is presented by Drs. Chen and Gould.

Patients with a confirmed or suspected diagnosis of lung cancer require accurate staging to delineate their appropriate treatment. This crucial process may involve noninvasive imaging modalities, including, for example, CT scanning and/or positron emission tomography (PET), and many cases will require invasive confirmation of disease at the primary site or at distant locations. An approach to staging for non-small cell lung cancer (NSCLC) is discussed by Dr. Tanoue, and the use of traditional as well as new bronchoscopic techniques for both diagnosis and staging is presented by Drs. El-Bayoumi and Silvestri. As outlined by Drs. Poonyagariyagorn and Mazzone, a rigorous physiological evaluation should also be undertaken in patients with early-stage lung cancer for whom surgical resection is recommended because many such patients will have underlying lung disease.

The treatment of patients with lung cancer should be approached in a multidisciplinary fashion. Patients with stage IA disease should receive surgical resection if medically feasible, but these patients account for a minority of all lung cancer cases. For most patients, treatment will involve a combination of chemotherapy, radiation, and/or surgery. New developments in radiotherapy, including stereotactic radiosurgery, are discussed by Drs. Decker and Wilson. An increasing understanding of the molecular pathogenesis of lung cancer has fostered the development of targeted therapies, as reviewed by Dr. Gettinger. Unfortunately, the various treatment interventions for lung cancer can be associated with toxicities and complications, an overview of which is given by Dr. Spiro and colleagues.

Lung cancer is receiving increasing attention in both public and scientific arenas. A growing appreciation of the burden of lung cancer mortality in the nation and the world is occurring at a time when our body of knowledge relating to epidemiology, pathogenesis, diagnosis, and treatment is expanding. The importance of lung cancer as a cause of morbidity and mortality is likely to continue into the foreseeable future. Clinicians must be aware of the multifaceted nature of this disease, building and maintaining skills in recognizing patients at risk, diagnosing disease, and appropriately recommending treatment based on accurate staging. We would like to thank all the authors who have contributed to this issue of Seminars in Respiratory and Critical Care Medicine dedicated to evolving concepts in lung cancer for their work in this effort.