| Abstract: |
Background: Among patients diagnosed with advanced non-small-cell lung carcinoma (NSCLC), African-Americans have lower survival rates than non-African-Americans. Whether this difference is due to innate characteristics of the disease in the two ethnicities or to disparities in health care is not known. We investigated whether the disparity in survival would persist when patients were treated with similar systemic therapies (i.e., in phase II and phase III Cancer and Leukemia Group B [CALGB] trials). Methods: We assessed 504 consecutive patients (458 non-African-American and 46 African-American) receiving systemic chemotherapy in CALGB studies for advanced NSCLC during the period from 1989 through 1998. Clinical and demographic characteristics, treatment received, and survival data were obtained from the CALGB database. Cox's proportional hazards model was used to assess the effect of race/ethnicity on survival after adjustment for other known prognostic factors. All statistical tests were two-sided. Results: The unadjusted 1-year survival rate was 22% (95% confidence interval [CI] = 13% to 38%) for African-American patients and 30% (95% CI = 26% to 35%) for non-African-American patients, a statistically significant difference (8%; 95% CI on the difference = 5% to 12%; P = .03). Multivariable adjustment for the effect of treatment arm, histology, and metastatic site at presentation did not alter the worse outcome for African-American patients. However, the effect of race/ethnicity disappeared after adjustment for performance status and weight loss. African-American patients were more likely than non-African-Americans to present with a poor performance status (83% versus 60%) and substantial weight loss (41% versus 27%) and to be unmarried (59% versus 28%), disabled (31% versus 15%), unemployed (17% versus 7%), and Medicaid recipients (30% versus 8%). Conclusions: The relationship that we observed between poor performance, weight loss, and socioeconomic status suggests that social circumstances lead to African-Americans presenting with poorer prognostic features. |
