Ann Thorac Surg 2003;76:S1363-S1366
© 2003 The Society of Thoracic Surgeons
Supplement: understanding disparities in cardiovascular and thoracic surgical outcomes in African-Americans
Lung cancer in african americans
Robert S. D. Higgins, MDa*,
Cleveland Lewis, MDb,
William H. Warren, MDa
a Rush-Presbyterian-St. Luke's Medical Center, Rush Medical College, Chicago, Illinois, USA
b Duke University Medical Center, Duke University School of Medicine, Durham, North Carolina, USA
* Address reprint requests to Dr Higgins, Department of Cardiovascular-Thoracic Surgery, Rush-Presbyterian-St. Luke's Medical Center, 1653 W. Congress Parkway, Chicago, IL 60612-3833, USA
e-mail: robert_higgins{at}rush.edu
Presented at the symposium on Understanding Disparities in Cardiovascular and Thoracic Surgical Outcomes in African Americans, San Diego, CA, Jan 30, 2003.
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Introduction
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Excluding squamous and basal cell carcinomas of the skin, lung cancer is the most frequently diagnosed cancer and remains the leading cause of death from cancer in the United States. It has been estimated that in 2001, 1.2 million new cases of cancer were diagnosed in the United States [1]. Data reported by the U.S. Bureau of Census, and the National Cancer Institute's Surveillance Epidemiology and End Results (SEER) program has been used to report important trends in diagnosis and treatment of cancer in the general population [2]. While the incidence of bronchopulmonary carcinoma in men has leveled off over the last decade, the overall incidence in women continues to rise. Moreover, since the mid 1980s, primary lung cancer has surpassed breast cancer as the leading cause of cancer death in women and now accounts for an estimated 25% of death from cancer in women [3] (Fig 1).
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Fig 1. The ten leading sites of estimated cancer deaths, by gender, in the United States, 2001 (excludes in situ carcinomas except urinary bladder). Percentages may not total 100% due to rounding. Reprinted with permission from Greenlee and coworkers [1].
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An in-depth evaluation of these statistics reveal disturbing variances in cancer incidence, stage at presentation, and mortality in certain subpopulations of our society. African-American patients have the highest overall incidence of cancer and are 33% more likely to die of cancer than Caucasians, and more than twice as likely to die from cancer as are Asian Pacific Islanders, American Indians, and Hispanics [1]. In 1999, cancer was the second leading cause of death among all racial and ethnic groups. The average annual age-adjusted incidence of lung cancer is 73.39 per 100,000 for African Americans and 54.31 per 100,000 for Caucasians [4, 5]. These statistics underscore the importance of smoking cessation programs, early diagnosis and treatment, and vigilant surveillance in all populations and especially in the African- American community.
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Risk factors associated with lung cancer
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Cigarette smoking is widely accepted to be the most important, and the most modifiable, risk factor for the development of lung cancer. It is important to note that smoking-related diseases (including ischemic heart disease, stroke, pneumonia, congestive heart failure, and chronic obstructive pulmonary disease) in addition to lung cancer contribute to observed disparities in mortality among racial groups and socioeconomic strata [6]. The incidence of smoking in the African-American community is higher than in other racial groups. However, among smokers, African Americans are inclined to smoke fewer cigarettes than Caucasians, and African- American adults are more likely to have initiated smoking after adolescence than their white counterparts [7].
It has been estimated that in 1988 there were 434,175 premature deaths in the United States attributed to cigarette smoking. The average number of years of potential life lost before age 65 attributed to smoking among African Americans (2471 years of potential life lost per 100,000 population) was more than twice that among Caucasians (1224.7 years of potential life lost per 100,000 population) [8]. Other risk factors for the development of lung cancer include occupational exposures, such as industrial carcinogens associated with heavy manufacturing and textile employment, and asbestosis. Here, African Americans comprise a disproportionately large percentage of the workforce [9].
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Hereditary predisposition to lung cancer
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In a comprehensive review of the current literature on lung cancer in African Americans, Stewart [10] explored the supposition that African Americans are more susceptible to lung cancer than other populations. In spite of anecdotal reports to the contrary, he concludes that the evidence is inconclusive. The current body of knowledge does not conclusively support the notion that genetic polymorphisms in the cytochrome P450 system (that have been clearly associated with increased risk of lung carcinoma.) exist disproportionately in the African-American population. He further suggests that a number of other factors, such as socioeconomic status, culture, education, the effect of carcinogen exposure, and access to appropriate medical attention, may lead to an increased incidence of lung cancer and decreased survival rate after diagnosis in African Americans [10].
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Treatment of lung cancer in african americans
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It is commonly accepted that complete surgical resection of early stage lung cancers can be curative and is the best hope for improving survival [11]. Unfortunately, historic trends have elucidated that African Americans are less likely to receive surgical treatment for resectable and potentially curable nonsmall cell lung carcinoma. Greenwald and coworkers [11] found that patients with stage I lung cancer in Seattle, San Francisco, and Detroit were less likely to undergo surgical resection if they were African American or of lower socioeconomic status than if they were white or of higher socioeconomic status. Similar disparities were seen in a study of the treatment of elderly in Virginia where African Americans faired less well than other racial groups [12]. African-American patients older than 65 years of age were 16% more likely to receive no therapy.
With these findings in mind, Gadgeel and colleagues [13] conducted a comprehensive evaluation of the impact of race on the management of lung cancer. In this study, a community-based cancer database was analyzed in order to characterize the clinicopathologic differences between African-American and white patients with lung cancer. Of the 48,318 eligible patients in the Detroit SEER database from 1973 to 1998, lung cancer incidence rates decreased for men of both races. From 1985 to 1998, however, this decrease was predominantly in white men, resulting in an increase in the racial differential between younger men of these races. The incidence of distant disease was higher among African Americans throughout the study period and there was a statistically significant difference in 2-year and 5-year survival rates in favor of the Caucasians. In a multivariate model, the relative risk of death for African-American patients relative to white patients was 1.24 for local stage (p < 0.0001), 1.14 for regional stage (p < 0.0001), and 1.03 for distant stage disease (p = not significant). The overall survival of African-American patients essentially remained unchanged, while survival rates in white men improved by 20% and in white women by 29% during the 26-year period of this study.
Although the documentation of data and trends in incidence and survival is important, full appreciation and understanding of these facts will only come with the acknowledgment that multiple factors contribute to the excess mortality in African-American patients. These other factors include access to appropriate health care and treatment, socioeconomic status, differences in lifestyle, and occupational exposure to carcinogens.
The issue of access to appropriate health care and treatment has been the subject of study for a number of investigators evaluating disparities in healthcare delivery and outcomes in African Americans. Appreciating that African Americans are less likely to receive surgical treatment than Caucasians, Bach and associates [14] undertook a population-based study to assess surgical treatment in patients 65 years of age or older with stage I or II resectable nonsmall cell lung cancer, and who lived in one of ten study areas of the SEER program. Demographic characteristics, diagnosis, stage of disease, and treatment was obtained from the database of 10,984 patients evaluated from 1985 to 1993. This information was correlated with Medicare inpatient discharge records. It was determined that the rate of surgery was 12.7% lower for African-American patients than for white patients (64.0% vs 76.7%, p < 0.0001; Fig 2).
The 5-year survival rate was also lower for African-American patients (26.4% vs 34.1%, p <0.001). However, among the patients undergoing surgery, survival was similar for the two racial groups (Fig 3).
The authors concluded that the lower survival rate among African-American patients with early stage nonsmall cell lung carcinoma compared with Caucasians was largely explained by the lower rate of surgical resection among the former (Fig 4). They further concluded that providing appropriate access and treatment, specifically surgical rsection for African-American patients, appeared to be a promising way of improving survival in this patient population.
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Fig 2. Survival of Medicare beneficiaries 65 years of age or older who were given a diagnosis of stage I or II nonsmall cell lung cancer between 1985 and 1993, according to race. Reprinted with permission from Bach and coworkers [14].
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Fig 3. Survival of Medicare beneficiaries 65 years of age or older who were given a diagnosis of stage I or II nonsmall cell lung cancer between 1985 and 1993, according to race. (green line = White patients with surgery; black line = Black patients with surgery; red line = White patients without surgery; blue line = Black patients without surgery.) Reprinted with permission from Bach and coworkers [14].
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Fig 4. Relation between the rate of surgical resection for stage I or II nonsmall cell lung cancer and 5-year survival in hypothetical cohorts of 1000 black and 1000 white Medicare beneficiaries 65 years of age or older. If 76.7% of the black patients had undergone surgery, 308 of them would be expected to be alive 5-years after diagnosis. Reprinted with permission from Bach and coworkers [14].
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Unfortunately, nearly 40% of the patients who present with lung cancer often have advanced disease. Blackstock and colleagues [15] recently evaluated outcomes among African-American and non-African-American patients with advanced nonsmall cell lung carcinoma. These investigators evaluated disparities in survival in patients being treated with systemic therapies for advanced nonsmall cell lung carcinomas during the period from 1989 through 1998. They found that the unadjusted 1-year survival rate was 22% for African-American patients and 30% for non-African-American patients. Multivariable adjustment for the effect of treatment on histology, metastatic site and presentation did not alter the poorer outcomes for African-American patients. On the other hand, the effect of race and 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, to have experienced substantial weight loss, to be disabled, to be unemployed, and to be Medicaid recipients. The authors concluded that the relationship between poor performance, weight loss and socioeconomic status suggest that social circumstances lead to African Americans presenting with poor prognostic features [15].
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Final thoughts
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The increased incidence of lung carcinoma in African Americans, subsequent absence of appropriate treatment, and poor prognosis is a disturbing epidemiologic phenomenon. Although the medical literature is replete with documentation of this problem, viable solutions with the potential to positively impact this disparity in healthcare outcomes will require renewed focus and commitment to the issue. An emphasis on access to and participation in smoking cessation and screening programs may have a direct impact on the incidence and presentation of lung cancer in African Americans, as well as society as a whole. Healthcare providers in the fields of primary care, medical oncology, radiotherapy, and thoracic surgery will need to underscore their commitment to early diagnosis and referral for appropriate surgical resection when appropriate. Cooperative studies between the National Cancer Institute, academic institutions, community-based initiatives, and state and local health officials must ensure that future initiatives are designed to minimize the disparities in outcomes, especially as it relates to the African-American population. Society as a whole will have to consider the impact of socioeconomic deprivation because it ultimately impacts health in our nation.
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References
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- Greenlee R., Hill-Harmon M., Murray T., et al. Cancer Statistics 2001. CA Cancer J Clin 2001;51:15-36.[Abstract/Free Full Text]
- Ries L.A., Eisner M.P., Kosary C.L., et al. SEER cancer statistics review 1973–1997. . Bethesda, MD: National Cancer Institute, 2000.
- Wingo P., Ries L.A., Giovino G.A., et al. Annual report to the nation on the status of cancer 1973–96, with a special section on lung cancer and tobacco smoking. J Natl Cancer Inst 1999;91:675-690.[Abstract/Free Full Text]
- Feldman R., Fulwood R.T. The three leading causes of death in African Americans: barriers to reducing excess disparity and to improving health behaviors. J Health Care Poor Underserved 1999;10:45-71.[Medline]
- Ries L.A., Eisner M.P., Kosary C.L., et al. Surveillance, epidemiology, and end results (SEER) program. SEER Cancer Statistics Review 1973–1997. . Bethesda, MD: National Cancer Institute, 2000.
- Wong M.D., Shapiro M.F., Boscardin W.J., et al. Contribution of major diseases to disparities in mortality. N Engl J Med 2002;347:1585-1592.[Abstract/Free Full Text]
- Current trends differences in the age of smoking initiation between blacks and whites—United States. Morbidity Mortality Weekly Report 1991;40:754–7
- Smoking attributable mortality, and years of potential life lost—United States. Morbidity Mortality Weekly Report 1991;40:62–3
- Swanson G., Lin C., Burns P. Diversity in the association between occupation and lung cancer among black and white men. Cancer Epidemiol Biomarkers Prev 1993;2:313-320.[Abstract]
- Stewart J. Lung carcinoma in African Americans. Cancer 2001;91:2476-2482.[Medline]
- Greenwald H., Pollissor N., Borgatta E., et al. Social factors treatment and survival in early stage non-small cell lung cancer. Am J Public Health 1998;88:1681-1684.[Abstract/Free Full Text]
- Smith T., Penberthy L., Desch C., et al. Differences in initial treatment patterns and outcomes of lung cancer in the elderly. Lung Cancer 1995;13:235-252.[Medline]
- Gadgeel S., Iverson R., Kan Y., et al. Impact of race in lung cancer: analysis of temporal trends from a surveillance, epidemiology and end results database. Chest 2001;120:55-63.[Abstract/Free Full Text]
- Bach P.B., Cramer L.D., Warren J.L., et al. Racial differences in the treatment of early stage lung cancer. N Engl J Med 1999;341:1198-1205.[Abstract/Free Full Text]
- Blackstock A.W., Herndon J.E., Pashett E.D., et al. Outcomes among African American/non-African American patients with advanced non-small cell lung carcinoma: report from the Cancer and Leukemia Group B. J Natl Cancer Inst 2002;94:284-290.[Abstract/Free Full Text]
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Introduction
Risk factors associated with...