Related Emory Lung Cancer Studies Reveal Survival Disparities at 2014 ACS Clinical Congress
Two Emory studies based on reviewed data from the National Cancer Data Base (NCDB) of the American College of Surgeons and the American Cancer Society were highlights of the October 2014 ACS Clinical Congress in San Francisco. The studies reached similar conclusions and were the largest database analyses of their types to date. Cardiothoracic surgeon-scientist Felix Fernandez, MD, was the senior author and team leader of both studies.
Data from an NCDB Participant User File (PUF) for non-small cell lung cancer was integral to the studies. PUFs contain patient level data that do not identify hospitals, health care providers, or patients. Winship Cancer Institute and Emory Department of Surgery oncology scientist Theresa Gillespie, PhD, is the PI and awardee of the file. Representation and analysis of the data was assisted by Winship's Biostatistics and Bioinformatics Shared Resource (BBISR). BBISR is supported by an NCI P30 Cancer Center Support Grant overseen by Walter Curran, MD, MPH, executive director of Winship.
Emory cardiothoracic surgeon-researcher Manu Sancheti, MD, presented "Risk Factors for 30-Day Mortality after Pulmonary Resection for Lung Cancer from the National Cancer Data Base: An Analysis of over 200,000 Patients" at the Posters of Exceptional Merit program of the ACS meeting, for which he received the Best Scientific Poster Presentation Award. The study team included Dr. Gillespie, Dr. Fernandez, and additional Emory faculty and staff Dana Nickleach, MA, Yuan Liu, PhD, Kristin Higgins, MD, Suresh Ramalingam, MD, and Joseph Lipscomb, PhD.
The study examined non-clinical factors associated with short-term mortality after pulmonary resection that could identify disparities in care, and focused on 215,758 patients from the NCDB who had surgical resection for non-small cell lung cancer during the period of 2003-2011. The team controlled for known clinical risk factors of short-term mortality, including comorbidity score, age, and extent of resection. They then reviewed other socioeconomic factors, including lack of health insurance, low income, low levels of education, and treatment at a non-academic center, and found that these factors were independently associated with higher 30-day mortality.
"Academic/research programs showed slight survival advantage, possibly due to the patient population being younger, more female, more likely to have insurance, and other factors," Dr. Sancheti says.
Thoracic surgery resident Onkar Khullar, MD, presented "Socioeconomic Risk Factors for Long-Term Mortality after Pulmonary Resection for Lung Cancer: An Analysis of More than 90,000 Patients from the National Cancer Data Base," which has been accepted for publication in the Journal of the American College of Surgeons. The other team members were the same as the prior study, minus Dr. Sancheti.
The study selected almost 235,000 patients from the NCDB diagnosed with non-small cell lung cancer between 2003 and 2006, approximately 93,000 of whom underwent surgery. About 60% of patients diagnosed with stage I cancer survived at least five years after surgery, compared to 40%, 31% and 20% for stage II, III, and IV, respectively.
After accounting for tumor stage, positive lymph nodes, and age at diagnosis, factors such as lack of insurance, lower income, and lower education level were associated with worse overall survival after surgery. For example, patients with the lowest education level and lowest income level had a 10% increased risk of death, and not being insured imparted a 23% increased risk. "While the stage of the cancer is a more important influence on patient outcomes," says Dr. Fernandez, "understanding all of the factors tied to survival can identify groups of people who need more attention for quality improvement."
The scope of the study did not allow for analysis of how the socioeconomic factors interacted, and acknowledged that the reported disparities required further, detailed investigation.