Airflow obstruction and/or emphysema have been associated with lung cancer risk, however this relationship and the joint occurrence of these conditions are not well studied in the African American population.
Describe the prevalence of airflow obstruction and/or emphysema in African Americans with lung cancer and evaluate their impact on the management and outcome of lung cancer.
Medical records were reviewed for 114 African Americans who had participated in population-based case-control studies of lung cancer and who sought medical care at the Karmanos Cancer Center in Detroit, Michigan. The medical records of these patients were reviewed for demographics, type and stage of lung cancer, spirometry, treatment and outcome. The chest CT scans around the time of the diagnosis of lung cancer were reviewed by a radiologist for evidence of emphysema. COPD was diagnosed when there were changes consistent with emphysema on CT scan and/or airflow obstruction by spirometry.
There were no differences by sex for age at lung cancer diagnosis (p=0.78) and tumor histology (p=0.43). Men were more likely to present at a later stage of lung cancer diagnosis compared to women (p=0.04) and women were more likely to have surgery than men (p=0.03). Overall, 94% of men and 78% of women in this population had spirometry and/or CT evidence of COPD. Men were somewhat more likely to have COPD diagnosed by either CT or spirometry than women (p=0.06), but the GOLD Classification scores did not differ by gender among those with spirometry-diagnosed COPD (p=0.34). Seventy eight percent of individuals who did not report a previous diagnosis of COPD had clinical evidence of COPD, whereas 94% of individuals who reported a previous diagnosis of COPD also had clinical evidence of COPD (p=0.03). Among individuals who had both spirometry and CT data available, 29% had CT evidence of emphysema but normal spirometry. No differences in COPD diagnosis (p=0.82) or emphysema diagnosis (p=0.51) were noted by tumor histology. Stage at diagnosis also did not differ by COPD or emphysema diagnosis (p=0.30 and p=0.06, respectively), nor did treatment modality (p=0.54 and p=0.10, respectively). Lung cancer patients with COPD diagnosed either via spirometry or CT did not show an increased risk of death compared to lung cancer patients without COPD after adjusting for age at diagnosis, gender and stage (HR=1.31 95% CI: 0.68-2.53).
There is a high incidence of COPD, emphysema in particular, in a selected group of African American patients with lung cancer. A significant number of these patients were not aware that they had COPD. There was no significant difference in the outcome of lung cancer in relation to the presence or absence of COPD.