Main Findings: Lung cancer patients with comorbid conditions such as chronic obstructive pulmonary disease, diabetes, or congestive heart failure had a higher risk of death than lung cancer patients without comorbid conditions.
Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research
Author: K.M. Monirul Islam, MD, PhD, an assistant professor in the Department of Epidemiology at the University of Nebraska Medical Center College of Public Health
Background: Lung cancer is the leading cause of cancer death in the United States, killing more than 135,000 people per year. More people die from lung cancer annually than die from breast, colon, and prostate cancers combined. The five-year survival rate is only about 17 percent. Currently, survival is the only significant measure of treatment success. Comorbid conditions can affect lung cancer survival in many ways, including complicating diagnostic evaluation, leading to less accurate disease staging, Islam said.
How the Study Was Conducted: To analyze the overall survival of lung cancer patients with or without comorbidities, Islam's research team conducted a population-based cohort study of 5,683 lung cancer patients identified from the Nebraska Cancer Registry and Nebraska Hospital Discharge Data. They also studied the overall survival in patients with any of the 14 comorbidities identified from the Charlson Comorbidity Index.
Results: Islam and colleagues found that among patients with localized lung cancer, those with one comorbidity had a 30 percent higher risk of mortality compared with those who had no comorbidity. Among patients with metastatic lung cancer, comorbidity had less impact on survival. This could be due to the very short survival in advanced-stage lung cancer patients, Islam said. Patients with comorbidity were found to have poorer survival at each stage, and the difference in survival between patients with and without comorbidity seemed to be greater in less advanced stages.
Author Comment: In an interview, Islam said, "The prevalence of comorbidities is higher in older lung cancer patients than patients who are younger. As the population of the United States ages, there will be a higher number of lung cancer patients with comorbidities at diagnosis. We found that lung cancer patients with comorbidities had about a nine-month average survival, which is shorter than the national average. We also found that 74 percent of the patients had one or more comorbidities. More than 50 percent of those with comorbidities had pulmonary disease, while 16 percent had diabetes, and 13 percent had congestive heart failure. Most previous studies aggregate all comorbidities into an index with little consideration of how a specific comorbid condition can impact lung cancer outcomes in an individual.
"Our results are based on cancer registry data from one state, so the results may not be generalizable to other populations. There is a need for a prospective study to confirm these results," Islam added. "We are planning to develop a lung cancer-specific comorbidity index using prospective data for the best estimate of the impact of individual comorbid conditions on survival."
Funding & Disclosures: This study was funded by the Patient-Centered Outcomes Research Institute, the Veterans Health Administration, the Nebraska Department of Health and Human Services, the UNMC College of Public Health, the National Science Foundation, and the Centers for Disease Control and Prevention Public Health Infrastructure. Islam declares no conflicts of interest.
About the American Association for Cancer Research
Founded in 1907, the American Association for Cancer Research (AACR) is the world's oldest and largest professional organization dedicated to advancing cancer research and its mission to prevent and cure cancer. AACR membership includes more than 35,000 laboratory, translational, and clinical researchers; population scientists; other health care professionals; and cancer advocates residing in 101 countries. The AACR marshals the full spectrum of expertise of the cancer community to accelerate progress in the prevention, biology, diagnosis, and treatment of cancer by annually convening more than 25 conferences and educational workshops, the largest of which is the AACR Annual Meeting with almost 19,300 attendees. In addition, the AACR publishes eight prestigious, peer-reviewed scientific journals and a magazine for cancer survivors, patients, and their caregivers. The AACR funds meritorious research directly as well as in cooperation with numerous cancer organizations. As the Scientific Partner of Stand Up To Cancer, the AACR provides expert peer review, grants administration, and scientific oversight of team science and individual investigator grants in cancer research that have the potential for near-term patient benefit. The AACR actively communicates with legislators and other policymakers about the value of cancer research and related biomedical science in saving lives from cancer. For more information about the AACR, visit http://www.