January 29, 2009
Study looks at survival disparities in lung cancer
Disparities in survival among black patients diagnosed with early-stage lung cancer are not seen when patients are recommended appropriate treatment, according to a report by UW researchers in the January issue of Archives of Surgery, one of the JAMA/Archives journals.
Lung cancer causes more deaths in the United States than any other cancer, according to background information in the article. Pulmonary resection—or surgery to remove a portion of the lung—provides the best chance for patients with early-stage disease to be cured.
“Black patients with early-stage lung cancer have lower five-year survival rates than white patients, and this difference in outcome has been attributed to lower rates of resection among black patients,” the authors write. “Several potential factors underlying racial differences in the receipt of surgical therapy include differences in pulmonary function, access to care, refusal of surgery, beliefs about tumor spread on air exposure at the time of operation and the possibility of cure without surgery, distrust of the health-care system and physicians, suboptimal patterns of patient and physician communication and health-care system and provider biases.” Of these, access to care is often considered the most important of factors underlying racial disparities.
Dr. Farhood Farjah, a resident in the Department of Surgery, and colleagues designed a study to address whether differences in survival persist when evaluating only patients who had been recommended to receive optimal therapy, in this case lung resection. Patients recommended for therapy were considered likely to have “cleared” at least one major hurdle of access to care. The investigators analyzed data from 17,739 patients who were diagnosed with lung cancer between 1992 and 2002 (average age 75, 89 percent white and 6 percent black) and who were recommended to receive surgical therapy. They tracked whether or not the patients underwent surgery, and their overall survival, through 2005.
While black patients recommended to surgery had lung resections less frequently than white patients (69 percent vs. 83 percent), the authors write, after adjustment, there was no significant association between race and death.
Several possible explanations exist for the differences in rates of surgery, the authors note, and these may be important for understanding patient decision-making and improving care delivery systems. Black patients may be more likely to refuse surgery than white patients, or may have more limited access to recommended care.
“Although these findings do not refute the likely roles of health-care system and provider biases and patient characteristics as important causal factors underlying health disparities, the findings do suggest that other factors (i.e., distrust, perceptions and beliefs about lung cancer and its treatment and limited access to subspecialty care) may have a more dominant role in causing disparities than previously recognized. The implication of these findings is that interventions designed to narrow gaps in health care should target structural aspects of care, providers and patients and communities at risk for lung cancer and suboptimal care.” The study findings suggest that referral of all patients with potentially curable lung cancer for consideration of lung resection may be a helpful tool in mitigating previously identified racial differences in survival.
Other UW authors were Drs. Douglas Wood, David Yanez, Thomas Vaughan, Rebecca Gaston Symons and David Flum, the corresponding author.
Farjah was supported by a Cancer Epidemiology and Biostatistics Training Grant and a Ruth L. Kirschstein National Research Service Award from the National Cancer Institute. Additional resources were available through the Department of Surgery, the Surgical Outcomes Research Center, and the Schilling family.