Smoking Out Cliches About RaceCigarette smoke may not be an equal opportunity carcinogen. According to a report in last week's New England Journal of Medicine, the same amount of cigarette smoke was associated with higher rates of lung cancer in African-Americans and Native Hawaiians than other groups. Despite comparable low-to moderate exposure, whites were about half as likely to develop lung cancer and Latinos and Asians were about half as likely as whites to develop it.
Sally Satel, MD
Medical Progress Today
February 2, 2006
The study certainly has health implications. "If you're an African-American and you think that by smoking 10 cigarettes a day that you're not going to be at increased risk of developing lung cancer, this study shows that you are," Dr. Joseph Cicenia, a pulmonologist at St. Vincent's Hospital Manhattan told the New York Daily News.
But study also has political implications. It rekindles a story line that BiDil brought into the spotlight recently. Approved by the FDA last June for the treatment of heart failure, BiDil - a combination drug containing a diuretic (hydralazine) and a nitric oxide enhancer (isosorbide dinitrate) - made headlines because it is the first drug ever to have been approved for use in a racial group, African Americans.
BiDil was demonstrated to be especially effective in black patients, most likely because of aspects of blood pressure physiology that vary by race. For reasons not well understood, individuals of African heritage are, on average, less likely to produce or release the molecule nitric oxide from the cells that line blood vessels, thus contributing to hypertension. Isosorbide seems to work by releasing nitric oxide at the blood vessel wall.
Naturally, news of BiDil's clinical promise inflamed the debate about the extent to which race has biological aspects. And, sure enough, the new lung cancer study provoked similar reactions.
"This feeds into the 19th-century notion that these categories really separate people in terms of their physical and biological characteristics," said Troy Duster of New York University. (Only the most scientifically illiterate today believe this straw man of race. As early as the 1770's, Johann Friedrich Blumenbach, considered the father of physical anthropology, remarked that "innumerable varieties of mankind run into each other by insensible degrees.")
Bioethicist Jeffrey Kahn of the University of Minnesota told the Washington Post that he worried the findings could be used to further discriminate: "The danger would be to sort of view lung cancer as a minority disease, and so something we don't have to worry as much about."
Kahn can calm down. The issue of "health disparities" is thriving. The Department of Health and Human Services has made it a priority area and health organizations like Robert Wood Johnson, Kaiser and Commonwealth Foundations have placed it high on their agendas. Unfortunately, though, part of the campaign to understand and combat differences in health status by race often includes an effort to eradicate physician bias. The idea of doctor bias acquired considerable and unmerited weight in both academic literature and the popular press. It enjoyed a great boost in visibility from a 2002 report from the Institute of Medicine, part of the National Academy of Sciences, called Unequal Treatment: Confronting Racial and Ethnic Disparities in Health Care, widely hailed as the authoritative study on health disparities. It concluded that the dynamics of the doctor-patient relationship-"bias," "prejudice," and "discrimination"-were a significant cause of the treatment differential and, by extension, of the poorer health of minorities.
Satisfying as this explanation may be for some people, it is wrong. Racially biased doctors are not a cause of poor minority health - a proposition almost impossible to prove in any case. It is the socioeconomic factors associated with race that generate the strongest momentum in driving the differences between races in both care and outcomes. Indeed, for answers to the race-related differences in health care, it turns out that the doctor's office is not the most rewarding place to look. White and black patients, on average, do not even visit the same population of physicians-making the idea of preferential treatment by individual doctors a far less compelling explanation for disparities in health.
Doctors whom black patients tend to see may not be in a position to provide optimal care. Furthermore, because health care varies a great deal depending on where people live, and because blacks are overrepresented in regions of the United States served by poorer health care facilities, disparities are destined to be, at least in part, a function of residence.
Nonetheless, many medical schools, health philanthropies, policymakers, and politicians are proceeding as if physician "bias" were an established fact.
Lung cancer was the subject of "bias" speculation when Peter Bach and colleagues at Memorial Sloan Kettering Cancer Center published a 1999 study in which they examined records of over 10,000 Medicare patients who received diagnoses of operable lung cancer. Seventy seven percent of white patients underwent surgery compared with 64% of black patients. Five years later, one-third of the white patients, but only one-quarter of the black patients, were still alive.
Those numbers understandably aroused concern, but many unanswered questions remained. One question was whether black patients refuse surgery more often than whites? The answer is yes. In 2003 researchers at the Philadelphia Veterans Affairs Medical Center presented their survey of over six hundred patients with pulmonary disease from three veterans hospital sites across the country. They found that more blacks than whites (61 percent versus 29 percent) maintained the folk belief that the spread of lung cancer was accelerated when the tumor was exposed to air during surgery and would oppose surgery because of this (19 percent versus 5 percent). A study of patients with operable lung cancer conducted at Detroit's Henry Ford Health System found refusal of surgery by black patients over three times more common than by whites. (Both whites and blacks were offered the surgery at similar rates.)
These studies are just a sample showing the concern of researchers with the social determinants of racial health differentials. In fact, big differences in health status are traceable to access to care and health literacy which is, in turn, a reflection of socioeconomic status, not race per se. The recent New York Times front page series on diabetes in the inner city captured it all - biological predispositions among blacks and Hispanics to type II diabetes coupled with the chaotic lives, the priorities of life that crowd out health concerns for poor people, the perverse Medicaid reimbursement schemes to providers wherein they get shortchanged on vital preventive care, (e.g., podiatric care; nutritional guidance).
This month's New England Journal article on lung cancer rates is judicious. The authors control for factors that might vary by group and influence the likelihood of developing cancer (e.g., occupation, diet, level of education) and they did find some differences but not of sufficient magnitude to account for the cancer disparities. Notably, non-smokers, irrespective of ethnic or racial group, had the same incidence of lung cancer. The theory that blacks are "constitutionally more susceptible" to the carcinogens in tobacco smoke is put forth alongside the possibility that blacks, as a group, may have a unique smoking style. Studies have shown they tend to inhale cigarette smoke more frequently and more deeply; perhaps, as well, the use of mentholated cigarettes (more popular among black smokers) is relevant.
Researchers, physicians and readers of newspaper health stories appreciate the complexity of race. That is, at minimum, they grasp that social aspects and biological aspects are intertwined. One can't help but think that it is the professional handwringers, like sociologist Duster and bioethicist Kahn, who keep worrying the thorn of racial discrimination. The public displays a common sense desire to improve health through many viable pathways and has moved past politically correct clichés.
- Christopher A. Haiman and others,"Ethnic and Racial Differences in the Smoking-Related Risk of Lung Cancer," New England Journal of Medicine 354, no. 4 (2006):333-42.
- Peter B. Bach and others, "Racial Differences in the Treatment of Early-Stage Lung Cancer," New England Journal of Medicine 341, no. 16 (1999):1198-1205.
- Mitchell L. Margolis and others, "Racial Differences Pertaining to a Belief About Lung Cancer Surgery: Results of a Multi-Center Study," Annals of Internal Medicine 139, no. 7 (2003): 558-63.
- Jennifer McCann and others, "Evaluation of the Causes for Racial Disparity in Surgical Treatment of Early Stage Lung Cancer," Chest 128, no. 5 (2005):3440-46.
Sally Satel, M.D., is a Resident Scholar at the American Enterprise Institute. She is also is co-author with Jonathan Klick of The Health Disparities Myth: Diagnosing the Treatment Gap, a new publication from the American Enterprise Institute Press, available at www.aei.org.