Racial Disparities in Lung Cancer

Despite achievements in the reduction of tobacco use in adults, cigarette smoking is a primary contributor to many of the leading causes of death in the United States, such as heart disease, lung cancer, and COPD. Though there have been decreases in cancer death rates in the past 2 decades, racial disparities in cancer mortality persist, particularly in regards to African American men (Table) (DeLancey et al. Cancer Epidemiol Biomarkers Prev. 2008:17[11]:2908). According to the American Cancer Society, African Americans continue to bear a disproportionate burden of cancer with the highest mortality of any ethnic group for all cancers combined and for most major cancers. Bronchogenic carcinoma is the second most common cancer in African American men and women. From 2000 to 2003, the average incidence of bronchogenic carcinoma was approximately 40% higher in African American men than in white men. From 2000 to 2003, the average annual death rate for bronchogenic carcinoma was 30% higher in African Americans compared with white subjects. African Americans also have a decreased likelihood of 5-year survival from cancer at all sites, at all stages of diagnosis (American Cancer Society. Cancer Facts & Figures for African Americans 2007-2008. Atlanta, GA: American Cancer Society, 2007).

Comparison of Lung Cancer Incidence and Death Rates 2000-2003

^a Rates are per 100,000 and age-adjusted to 2000 US standard population.
^b Absolute difference = African American minus Caucasian rate.
^c Ratios of rates in African Americans divided by those of Caucasians are based on two decimal places.

Source: American Cancer Society. Cancer Facts and Figures for African Americans 2007-2008. Atlanta; 2007.

It is well known that risk for lung cancer varies among smokers (Bach et al. J Natl Can Inst. 2003;95[6]:470). Despite the fact that African Americans initiate smoking at later ages than white subjects and smoke fewer cigarettes per day (Muscat et al. Cancer. 2005;103[7]:1420), African American men have higher lung cancer incidence and mortality (Harris et al. Int J Epidemiol. 1993;22[4]:592; Alberg et al. Semin Respir Crit Care Med. 2008;29[3]:223; Gadgeel et al. Cancer Metastasis Rev. 2003;22[1]:39; Jemal et al. CA Cancer J Clin. 2009;59[4]:225). The reasons for this greater prevalence and mortality have not been conclusively elucidated. Potential explanations may be biological, genetic, or related to socioeconomic status, where poverty, education, or lack of or insufficient insurance may be factors. Other reported mechanisms include distrust of the medical establishment (Gordon et al. J Clin Oncol. 2006;24[6]:904), refusal of operative intervention (McCann et al. Chest. 2005; 128[5]:3440), and treatment bias.

Differences in nicotine metabolism and smoking behaviors have been reported between racial groups. It has been demonstrated that African Americans have higher serum cotinine levels per cigarette smoked, slower clearance of cotinine, and higher intake of nicotine per cigarette smoked (Perez-Stable et al. JAMA. 1998;280[2]:152). Other studies have documented that African Americans exhibit more loss of lung function per cigarette smoked (Dransfield et al. Respir Med. 2006;100[6]:1110).

Disparities in tobacco-related knowledge have been reported. Finney and colleagues analyzed data from the National Cancer Institute’s Heath Information National Trends Survey to determine knowledge of smoking risk and cancer prevention. Knowledge of lung cancer mortality was lower among women, older adults, and non-Hispanic blacks (Finney et al. Nicotine Tob Res. 2008;10[10]:1559). In an analysis of 4,756 smokers who participated in the 2005 National Health Interview Survey (NHIS), African American and Hispanic smokers had significantly lower odds of being asked about tobacco use, adjusted odds ratio (AOR) = 0.70 and 0.69, respectively; being advised to quit smoking (AOR = 0.72 and 0.64, respectively); or having used a smoking cessation aid in the past year (AOR = 0.6 and 0.59, respectively) (Cokkinides et al. Am J Prev Med. 2008:34[5]:404).

When lung cancer is localized at diagnosis, the 5-year relative survival rate for African Americans is 42%, though only 14% of lung cancer cases are diagnosed at this stage (American Cancer Society). Compared with white subjects, African Americans tend to present with lung cancer at a higher stage (Berger et al. Curr Probl Cancer. 2007:31[3]:202). In a study of race and sex differences in the receipt of timely and appropriate lung cancer treatment, Shugarman and colleagues analyzed Surveillance Epidemiology and End Result (SEER) data linked to Medicare claims for individuals diagnosed with non-small cell lung cancer. For claims analyzed between 1995 and 1999 in individuals with stage I and stage II cancer, African Americans were 66% less likely to receive timely and appropriate therapy in comparison to white subjects. Compared with white men, African American men were the least likely to receive resection (22 % vs 44%). African Americans were 43% less likely to receive timely surgery, chemotherapy, or radiation for stage III disease and 51% less likely to receive timely chemotherapy for stage IV disease (Shugarman et al. Medical Care. 2009;47[7]:774). Farjah and colleagues analyzed SEER data for stage I and stage II lung cancers diagnosed between 1992 and 2002.These authors did not find any statistically significant differences in the racial distribution of cancer stage or histologic findings. In this cohort of 17,739 subjects (89% white and 6% African American), African American patients underwent resection less often, 69% vs 83% (P < .0001, [OR 0.43, 95% CI 0.36 - 0.52]) (Farjah et al. Arch Surg. 2009;144[1]:14). In surprising contrast to an older series (Bach et al. N Engl J Med. 1999:341[16]:1198), the lack of operative intervention did not result in a detectable mortality difference. This unexpected finding was speculated to be due to inadequate risk adjustment or unmeasured patient selection factors, such as intrinsic lung function, which affect outcomes. In areas with unlimited access to medical care, such as military facilities or Veteran’s Administration facilities, these large variations in outcome are largely mitigated (Mulligan et al. Cancer Epidemiol Biomarkers Prev. 2006;15[1]: 25; Greenwald et al. Am J Public Health. 1998;88[11]:1681)

Even for those in high risk groups, there are no consensus guidelines for lung cancer screening (Flenaugh et al. Clin Chest Med. 2006:27[3]:431; Smith et al. CA Cancer J Clin 2009;59[1]:27), though a lung cancer risk prediction model has been developed and validated specifically for African Americans (Etzel et al. Cancer Prev Res 2008;1[4]:255). As lung cancer is primarily caused by tobacco smoking, many cases of lung cancer are, therefore, preventable. The prevalence of smoking in African American men was estimated to be 27.6% in 2006 (MMWR Morb Mortal Wkly Rpt 2007:56[44]:1157). This exceeds the threshold of 12% or less targeted for reduction in smoking by 2010. Of the 45.3 million adults in the United States who were current smokers in 2006, men (23.9%) were more likely to smoke than women (18%), and African Americans (23%) were more likely to be current smokers than whites (21.9%).

Tobacco smoking, and its risk for lung cancer, is increasingly concentrated in populations with limited resources whose lives and smoking behaviors may be affected by stress, violence, and unemployment (Irvin Vidrine et al. Curr Oncol Rep. 2009;11[6]: 475). Adequate education about the risks of cigarette smoking and comprehensive, culturally competent smoking cessation programs targeted to high risk groups need immediate implementation.

Dr. Marilyn G. Foreman, FCCP,
Pulmonary and Critical Care Medicine;
Dr. Olutola Akiode,
Department of Medicine; and
Dr. Eric Flenaugh, FCCP,
Pulmonary and Critical Care Medicine
Morehouse School of Medicine
Atlanta, GA

Commentary
This review on racial disparities in lung cancer by Dr. Marilyn Foreman and colleagues is excellent and quite timely, as our nation is struggling with the difficult task of health reform. Dr. Foreman reminds us that substantial racial disparities continue in the incidence, mortality and risk of lung cancer.

A report from the Agency for Healthcare Research and Quality (AHRQ), the 2006 National Healthcare Disparities Report (www.ahrq.gov/qual/nhdr06/nhdr06.htm. Accessed January 20, 2010), notes that disparities related to race, ethnicity, and socioeconomic status “still pervade the American health care system.”

A recent report by the Urban Institute (www.urban.org/publications/411962.html, accessed January 20, 2010) estimated that in 2009, disparities among African Americans, Hispanics, and non-Hispanic whites would cost the health-care system $23.9 billion, and over the 10-year period from 2009 through 2018, the total cost will be $337 billion (including $220 billion for Medicare).

So, in addition to the moral imperative for solving the disparities in health care, there are strong economic imperatives. We must have health reform that is responsive to the health needs of the underserved of this nation.

Dr. Alvin V. Thomas, Jr, FCCP
Past President, ACCP