Alcohol and Alcoholism Advance Access originally published online on January 25, 2007
Alcohol and Alcoholism 2007 42(2):125-130; doi:10.1093/alcalc/agl121
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
SECULAR TREND IN U.S. BLACKWHITE DISPARITIES IN SELECTED ALCOHOL-RELATED CANCER INCIDENCE RATES
Connecticut Tumor Registry, Connecticut Department of Public Health, 410 Capitol Ave., Hartford, CT 06134-0308, USA
Anthony.polednak{at}po.state.ct.us
Received 19 September 2006; first review notified 1 December 2006; in revised form 8 December 2006; accepted 12 December 2006
| ABSTRACT |
|---|
|
|
|---|
Aims: To examine secular trends in incidence rates for the cancer types most strongly associated with alcohol in African Americans (blacks) and whites. Methods: Average annual age-standardized incidence rates (ASIRs) for years of diagnosis 19731975 through 20002002 were analysed for squamous cell carcinomas of the oral cavity pharynx, oesophagus and larynx in U.S. blacks and whites by sex, using data from a group of high-quality population-based cancer registries. Also examined were National Health Interview Survey (NHIS) results on prevalence of current drinking and cigarette smoking among the U.S. population, and U.S. age-standardized mortality rates for alcoholic liver disease-damage from 1979 to 2003. Results: In 19731975, ASIRs were greater in blacks than whites for cancers of the oesophagus and larynx but not oral cavity pharynx, and peaks in the disparity reached in the 1980s were followed by declines except for laryngeal cancer (the cancer most strongly associated with tobacco). By 20002002, blackwhite disparities in ASIRs were highest for oesophagus (black/white ratio 4.3 for males and 2.9 for females) but lower for laryngeal cancer and small or non-existent for oral cavity pharynx. NHIS data showed that by the 1970s the U.S. black/white ratios of prevalence were slightly > 1.0 for current smoking but 0.9 (and 0.7 by 1997 and 2003) for current drinking. Disparities in alcoholic liver disease had disappeared by 2003. Conclusions: Further declines in blackwhite disparities in cancer rates may occur (allowing for lag times), but the larger disparities for oesophageal cancer support the need to explore etiologic factors interacting with alcohol that continue to differ in prevalence between blacks and whites.
| INTRODUCTION |
|---|
|
|
|---|
The strongest associations between alcohol use and cancer risk are those relating to cancersof the oral cvity, pharynx, oesophagus (squamous cell carcinoma only) and larynx, with strong interactions between alcohol and tobacco (especially for the pharynx) but a stronger association of laryngeal cancer with tobacco than with alcohol (Adami et al., 2002
Trends of incidence rates for these cancers diagnosed since 1973 have been reported for U.S. black and white populations in the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER). Programmes of high-quality population-based cancer registries are often used to estimate trends in the entire U.S. (Jemal et al., 2004
; Ries et al., 2005
). However, data by histologic category are not routinely included, and the explanation for trends by race has not been discussed. The present report focuses on squamous cell carcinomas, which are most strongly associated with alcohol and tobacco, and considers trends in alcohol and tobacco use, the only established risk factors for these cancers, along with the protective effect of fruits and vegetables (Adami et al., 2002
).
| METHODS |
|---|
|
|
|---|
Data are available for seven SEER registries starting with cancer diagnoses in 1973 (i.e. Connecticut, metropolitan Detroit, Michigan, Hawaii, Iowa, New Mexico, San Francisco, Oakland, California and Utah), for the Seattle-Puget Sound Washington area starting with 1974, and for metropolitan Atlanta, Georgia, starting with 1975 (Ries et al., 2005
International Classification of Diseases for Oncology (ICD-O) Version-3 site codes were used to select cancers of the oral cavity and pharynx (site codes C000-148), oesophagus (C150159) and larynx (C320329). Histologic type is important in epidemiologic studies such as analyses of temporal trends in incidence rates (Muir and Weiland, 1995
; Thomas and Sobin, 1995
; Adami et al., 2000. For this study, squamous cell carcinomas (ICD-O-3 morphology codes 80518084) were selected, which have accounted for >90% of upper aerodigestive tract cancers except for oesophagus. For the oesophagus, adenocarcinomas have increased since the 1970s, due to risk factors other than alcohol use (Muir and Weiland, 1995
; Thomas and Sobin, 1995
; Adami et al., 2002
). Other alcohol-related cancer sites were excluded, such as breast and liver, because of weaker associations with alcohol (Zeka et al., 2003
) and because of the impact of trends in other factors such as cancer screening rates (for breast) and hepatitis infection (for liver) (Yuan et al., 2004
).
The SEER*Stat computer program (version 6.1.4) (National Cancer Institute, 2005) was used to obtain average annual age-standardized incidence rates (ASIRs), by the direct method, using age-specific incidence rates at five-year age intervals and weights based on the age distribution of the U.S. population in 2000. Average annual ASIRs per 100,000 per year were calculated at three-year time intervals from 1973 to 1975 through 20002002. Confidence intervals (CI) (95% CIs) on ASIRs were also calculated (National Cancer Institute, 2005).
SEER registries do not routinely collect information on alcohol and tobacco use histories of individual cancer patients. For interpreting the secular trends in ASIRs by race, data on U.S. per capita apparent alcohol consumption are not available by race, and historical data on alcohol use among U.S. blacks are limited (Dufour, 1998
). The National Health Interview Survey (NHIS) of samples of the U.S. population has included various questions (differing in wording) on alcohol use. Published data for U.S. blacks and whites are not sex-specific in reports from the earliest surveys (in the 1970s and 1980s) (Schoenborn and Danchik, 1980
; Schoenborn and Cohen, 1986
) but include drinking 5 plus drinks/day on any day (or on any "occasion" in some surveys) in the past year among current drinkers. NHIS data for selected calendar years on prevalence of current cigarette smoking by race for the entire U.S. (U.S. Department of Health and Human Services, 1998; National Center for Health Statistics, 2004, 2005) are also tabulated. Interpretation of secular trends in cancer rates is complicated by long latency periods (often, several decades) between exposure to a carcinogen (e.g. alcohol) and diagnosis of cancer in an individual, which are reflected at the population level by lag times between changes in prevalence rates for risk factors and changes in cancer rates. This also holds true for alcohol-related diseases other than cancer. For comparison with cancer incidence rates, age-standardized mortality rates (using the 2000 U.S. population as standard) from alcoholic liver disease-damage (100% attributable to alcohol) were used; data for 19792003 were available from the Centers for Disease Control and Prevention (CDC Wonder, http://wonder.cdc.gov), using ICD-9 codes 571.0571.3 for 19791998 and ICD-10 code K70 for 19992003.
| RESULTS |
|---|
|
|
|---|
The average annual ASIRs (per 100,000) for squamous cell carcinoma of the oesophagus in blacks had greatly surpassed those in whites (i.e. a black/white ratio 4.2 for males and 3.0 for females) in 19731975, when the blackwhite disparity was smaller for laryngeal cancer and not consistent by sex for oral cavitypharyngeal cancer (Table 1). Temporal increases in ASIRs from the 1970s through the 1980s were evident for blacks for each cancer site group, but not clearly apparent for whites. Blackwhite disparities peaked in magnitude in the 1980s for each cancer site group, and by 20002002 had returned close to those seen in the 1970s, except for an increased disparity for laryngeal cancer in males. Most ASIRs in 20002002 also had returned to roughly the same level as those in 19731975, except that the ASIRs for oesophagus were much lower in 20002002 than in 19731975 (especially for males).
|
Using published NHIS data for selected years (Table 2), the prevalence of adult current cigarette smokers was higher in U.S. blacks than whites in 1974, especially in males, and a small blackwhite difference persisted through 2003 in males but not females. The prevalence of current drinkers was already lower in blacks than whites by 1977, and the black/white ratio declined slightly (owing to a larger decline in blacks than whites) from 1977 to 1983 but with no clear subsequent decline. The prevalence of adult drinkers reporting drinking 5 plus drinks on any day (or "any occasion" in the early surveys) in the past year was also slightly lower in black than white adults (aged over 20 years); while the prevalence increased from 1977 to 1983 (for ages over 18 years) in both races, the black/white ratio declined slightly. Data by sex within each race were not published from the early NHIS surveys, but black/white ratios of prevalence of 5 plus drinks/day among current drinkers (not tabulated) were 32.0/44.4 (or 0.7) for males and 15.0/20.9 (0.7) for females in 1997, and 31.0/41.3 (0.8) for males and 12.2/21/4 (0.6) for females in 2003 (National Center for Health Statistics, 2005).
|
The U.S. blackwhite disparity (ratio) in mortality rates from alcoholic liver disease-damage declined after 1989, and by 2003, ratios were lower in blacks than whites (Table 2). A lag time is apparent between the attainment of a slightly lower prevalence of current alcohol users in blacks than in whites (by the 1970s) and equality of blackwhite mortality rates (by 2003).
| DISCUSSION |
|---|
|
|
|---|
Study limitations include the use of SEER Program data. The populations covered by all the original SEER Program areas combined differed sociodemographically from the entire U.S. The use of SEER may underestimate cancer mortality rates (especially for tobacco-related cancers) compared to the entire U.S.; however, temporal trends may be more representative (Hankey et al., 1999
Within these study limitations, and in the absence of extensive historical data on alcohol use patterns in the U.S. black population (Dufour, 1998
), the rising blackwhite disparities in ASIRs through the 1980s (Table 1) is a continuation of an earlier pattern shown for cancer mortality rates (Henschke et al., 1973
). This could reflect (at least in part) the delayed effects of the probable rise of alcohol use among blacks starting in the 1920s and 1930s with migrations of black populations from the South (Herd, 1985
). Similarly, after a lag time, excess liver cirrhosis mortality rates in blacks versus whites also became evident by the mid-1950s (Herd, 1985
; Dufour, 1998
). Declines in black/white ratios of ASIRs for the alcohol-related cancers, after peaking in the 1980s (Table 1), could reflect the delayed effect (after a lag time) of declines in black/white ratios in prevalence of current (and "binge") drinking (as reflected in the absence of a blackwhite disparity in U.S. population surveys in the 1970s) (Table 2). Alcohol-related cirrhosis mortality rates (Dufour, 1998
) and blackwhite disparities in these rates (especially in males) peaked in the 1970s (Mann et al., 2003
) and the large (i.e. two-fold) blackwhite differences in alcoholic liver disease-damage mortality rates in the 1970s had disappeared by around 2000 (Table 2) (Mann et al., 2003
; NIAAA, 2005), strongly suggesting an impact of declining blackwhite differences in alcohol use. Lag times for ASIRs to be affected by population changes in alcohol consumption, however, may differ by cancer site/type. In addition, trends in ASIRs for alcohol-related cancers are affected by trends in tobacco use, as well as in other etiologic factors that may differ by cancer site/type.
For oral cavity pharynx cancer, the blackwhite disparity in ASIRs in males declined from a peak in 19881990 to a small difference in 20002002 (albeit still statistically significant in males) and the ASIR was lower for black than white for females in 20002002 (Table 1).
For laryngeal cancer, more strongly associated with tobacco than alcohol, the persistence of blackwhite differences in ASIRs (Table 1) could reflect (at least in part) lag times required for the convergence in prevalence rates of current smoking in black and white adults (Table 2) to affect ASIRs; only the black/white ratio of current smoking among U.S. females had fallen below 1.0 by 2003 (Table 2). While only 59 years of simultaneous cessation of both alcohol and tobacco use may reduce the risk of oesophageal cancer by 75% (Castellsague et al., 2000
), longer intervals may be needed for substantial reductions in risk for laryngeal cancer (Altieri et al., 2002
). Thus, declines in ASIRs for laryngeal cancers in blacks, and in blackwhite disparities in ASIRs, may occur in the future; so continued surveillance is needed, using data from SEER and other cancer registries. However, as shown for lung cancer, blackwhite differences in smoking-related cancer rates are not explained by simple measures of smoking (e.g. cigarettes/day, age started and age quit) and may involve cigarette type, smoking patterns (e.g., puff frequency) and metabolism of cigarette smoke constituents (Pinsky, 2006
).
For oesophageal cancer, a large blackwhite ratio disparity in the ASIR was attained earlier than for the other cancers (Table 1), as also shown in the Third National Cancer Survey (in 19671971) (Devesa and Silverman, 1978
). A large blackwhite disparity, based on lower ASIRs than in the past, persisted in 20002002 for oesophageal cancer (Table 1). This pattern suggests the influence of an etiologic factor(s), other than alcohol and tobacco, that has continued to differ in prevalence between U.S. blacks and whites. This view is consistent with findings from a case-control epidemiologic study of squamous cell oesophageal cancer in males (in Atlanta, Detroit and New Jersey), showing higher risks for blacks than whites at each level of alcohol intake, not explained by type of alcoholic beverage, suggesting that unidentified factors (possibly, dietary or viral) may interact with alcohol in explaining the higher ASIRs in blacks than whites (Brown et al., 1997
, 2001
).
A protective effect of high fruit and vegetable intake on risk of oropharyngeal cancer has been reported for chronic users of alcohol and/or tobacco and not in non-users (Kreimer et al., 2006
). Low intake of fruits and vegetables is a risk factor for oesophageal cancer in both blacks and whites (Brown et al., 1997
, 2001
), but consumption has changed little in U.S. whites and blacks in recent decades and blackwhite differences in intake are small. Intake of certain vegetables is higher in blacks than whites (Popkin et al., 1996
; Briefel and Johnson, 2004
). Human papillomavirus (HPV) is an accepted etiologic factor only for a subset of oral pharyngeal (especially, tonsil) cancers (Herrero, 2003
), but a case-control study in a high-risk population (in China) did not support a major role for HPV in oesophageal squamous cell carcinoma (in view of the low HPV prevalence in the cases) (Kamangar et al., 2006
). Dietary risk factors for squamous cell oesophageal cancer other than fruits and vegetables, interacting with alcohol use, should be explored in blacks and whites.
Although "race" is a socially defined variable, populations differ in frequencies of various genetic polymorphisms including those relevant to metabolism of alcohol. An aldehyde dehydrogenase 2 (ALDH2) polymorphism, ALDH2*2, associated with risk of oesophageal cancer in certain Asian populations, is rare or non-existent in non-Asian groups, while other ALDH2 variants were associated (interacting with alcohol consumption) with risk of upper aerodigestive tract cancers (most strongly with squamous cell carcinoma of the oesophagus) in an unconfirmed study of Europeans (Hashibe et al., 2006
) but apparently have not yet been studied in African-origin groups. For the ADH1 C allele, which codes for an enzyme that metabolizes alcohol (i.e. "fast" metabolism) to acetaldehyde (a potential cocarcinogen), the homozygote ADH1 C*1/1 (vs. the heterozygote ADH1 C*1/2) has been reported in some (but not all) studies as more frequent among heavy drinking patients with upper aerodigestive cancers versus those with non-cancerous conditions (reviewed by Brennan et al., 2004
; Visapaa et al., 2004
; Homann et al., 2006
). A hypothesis for blackwhite differences in oesophageal SCC ASIRs, however, would seem to require an etiologic factor (interacting with alcohol use) rather specific to that cancer type, in view of the specific secular trend in ASIRs for blacks versus whites (Table 1), whereas a high frequency of ADH1 C*1/1 has been reported for other cancers including oral cancer and head and neck cancers (Harty et al., 1997
; Visapaa et al., 2004
; Homann et al., 2006
). Also, the ADH1 C*1 gene (with low frequency in East Asia) may not be more frequent in Africa than in Europe/Southwestern Asia (Osier et al., 2002
).
| ACKNOWLEDGEMENTS |
|---|
The work reported in this paper was supported by Contract N01-PC-35133 between the National Cancer Institute and the Connecticut Department of Public Health.
| REFERENCES |
|---|
|
|
|---|
In Adami H. O., Hunter D., Trichopoulos D. (Eds.). Textbook of Cancer Epidemiology (2002) (Oxford University Press, New York).
Altieri A., Bosetti C., Talamini R., et al. (2002) Cessation of smoking and drinking and the risk of laryngeal cancer. British Journal of Cancer 87:12271229.[CrossRef][Web of Science][Medline]
Brennan P., Lewis S., Hashibe M., et al. (2004) Pooled analysis of alcohol dehydrogenase genotypes and head and neck cancer: a HuGE review. American Journal of Epidemiology 159:116.
Briefel R. B. and Johnson C. L. (2004) Secular trends in dietary intake in the United States. Annual Review of Nutrition 24:401431.[CrossRef][Web of Science][Medline]
Brown L. M., Hoover R., Gridley G., et al. (1997) Drinking practices and risk of squamous cell esophageal cancer among black and white men in the United States. Cancer Causes and Control 8:605609.[CrossRef][Web of Science][Medline]
Brown L. M., Hoover R., Silverman D., et al. (2001) Excess incidence of squamous cell esophageal cancer among U.S. black men: role of social class and other factors. American Journal of Epidemiology 153:114122.
Castellsague X., Munoz N., De Stefani E., et al. (2000) Smoking and drinking cessation and risk of esophageal cancer (Spain). Cancer Causes and Control 11:813818.[CrossRef][Web of Science][Medline]
Corrao G., Bagnardi V., Zambon A., et al. (2004) A meta-analysis of alcohol consumption and the risk of 15 diseases. Preventive Medicine 38:613619.[CrossRef][Web of Science][Medline]
Devesa S. S. and Silverman D. T. (1978) Cancer incidence and mortality trends in the United States: 193574. Journal of the National Cancer Institute 60:545571.[Web of Science][Medline]
Dufour M. C. (1998) Alcohol use. In Brownson R. C., Remington P. L., Davis J. R. (Eds.). Chronic Disease Epidemiology and Control(American Public Health Association, Washington, DC) pp. 149190.
Galvan F. H. and Caetano R. (2003) Alcohol use and related problems among ethnic minorities in the United States. Alcohol Research and Health 27:8794.[Web of Science][Medline]
Greenfield T. K., Midanik L. T., Rogers J. D. (2000) A 10-year national trend study of alcohol consumption, 19841995: Is the period of declining drinking over? American Journal of Public Health 90:4752.
Hankey B. F., Ries L. A., Edwards B. K. (1999) The surveillance, epidemiology, and end results program: a national resource. Cancer Epidemiology Biomarkers and Prevention 8:11171121.
Harford T. C., Grant B. F., Yi H., et al. (2005) Patterns of DSM-IV alcohol abuse and dependence criteria among adolescents and adults: results from the 2001 National Household Survey on Drug Abuse. Alcoholism Clinical and Experimental Research 29:810828.[CrossRef][Web of Science][Medline]
Harty L. C., Caporaso N. E., Hayes R. B., et al. (1997) Alcohol dehydrogenase 3 genotype and risk of oral cavity and pharyngeal cancers. Journal of the National Cancer Institute 89:16981705.[Abstract]
Hashibe M., Boffetta P., Zaridze D., et al. (2006) Evidence for an important role of alcohol- and aldehyde-metabolizing genes in cancers of the upper aerodigestive tract. Cancer Epidemiology Biomarkers and Prevention 15:696703.
Henschke U. K., Leffall L. D., Mason C. H., et al. (1973) Alarming increase of the cancer mortality in the U.S. black population (19501967). Cancer 31:763768.[CrossRef][Web of Science][Medline]
Herd D. (1985) Migration, cultural transformation and the rise of black liver cirrhosis mortality. British Journal of Addiction 80:397410.[CrossRef][Web of Science][Medline]
Herrero R. (2003) Human papillomavirus and cancer of the upper aerodigestive tract. Journal of the National Cancer Institute Monographs 31:4751.[Medline]
Homann N., Stickel F., Konig I. R., et al. (2006) Alcohol dehydrogenase 1 C*1 allele is a genetic marker for alcohol-associated cancer in heavy drinkers. International Journal of Cancer 118:19982002.[CrossRef][Web of Science][Medline]
Jemal A., Clegg L. X., Ward E., et al. (2004) Annual report to the nation on the status of cancer, 19752001, with a special feature regarding survival. Cancer 101:327.[CrossRef][Web of Science][Medline]
Kamangar F., Qiao Y. L., Schiller J. T., et al. (2006) Human papillomavirus serology and the risk of esophageal and gastric cancers: Results from a cohort in a high-risk region of China. International Journal of Cancer 119:579584.[CrossRef][Web of Science][Medline]
Kreimer A. R., Randi G., Herrero R., et al. (2006) Diet and body mass, and oral and oropharyngeal squamous cell carcinomas: analysis from the IARC multinational case-control study. International Journal of Cancer 118:22932297.[CrossRef][Web of Science][Medline]
Mann R. E., Smart R. G., Govoni R. (2003) The epidemiology of alcoholic liver disease. Alcohol Research and Health 27:209219.[Web of Science][Medline]
Cancer in North America, 19972001. Volume Three: NAACCR Combined Incidence Rates. (2004) (North American Association of Central Cancer RegistriesIn McLaughlin C. C., Hotes J. L., Wu X. C. (Eds.), et al. , Springfield, IL).
Merrill R. M. and Dearden K. A. (2004) How representative are the surveillance, epidemiology, and end results (SEER) Program cancer data in the United States? Cancer Causes and Control 5:10271034.
Racial/Ethnic Patterns of Cancer in the United States 19881992. (1996) (National Cancer InstituteIn Miller B. A., Kolonel L. N., Bernstein L. (Eds.), et al. , Bethesda, MD) NIH Pub. No. 96-4104.
Moller H. and Tonnesen H. (1997) Alcohol drinking, social class and cancer. In Kogevinas M., Pearce N., Susser M., Boffetta P. (Eds.). Social Inequalities and Cancer(International Agency for Research on Cancer (IARC), Lyon, France) pp. 251263 IARC Scientific Publication No. 138, Lyon France.
Muir C. and Weiland L. (1995) Upper aerodigestive tract cancers. Cancer 75:147153.[CrossRef][Web of Science][Medline]
National Cancer Institute. (2005) Surveillance, Epidemiology, and End Results (SEER) Program Public-Use CD-ROM (19732002). National Cancer Institute, DCPC, Surveillance Program, Cancer Statistics Branch, released April 2005.
National Center for Health Statistics. (2004) Health United States, 2004. (National Center for Health Statistics, Hyattsville, MD).
National Center for Health Statistics. (2005) Health United States, 2005 with Chartbook on Trends in the Health of Americans. (National Center for Health Statistics, Hyattsville, MD).
National Institute on Alcohol Abuse and Alcoholism (NIAAA). (2005) Graphics gallery: Age-adjusted death rates of liver cirrhosis by sex and race, United States, 19702000. www.niaaa.nih.gov/gallery/epidemiology/cirr2.htm.
Osier M. V., Pakstis A. J., Soodyall H., et al. (2002) A global perspective on genetic variation at the AHD genes reveals unusual patterns of linkage disequilibrium and diversity. American Journal of Human Genetics 71:8499.[CrossRef][Web of Science][Medline]
Pinsky P. F. (2006) Racial and ethnic differences in lung cancer incidence: How much is explained by differences in smoking patterns? (United States). Cancer Causes and Control 17:10171024.[CrossRef][Web of Science][Medline]
Popkin B. M., Siega-Riz A. M., Haines P. S. (1996) A comparison of dietary trends among racial and socioeconomic groups in the United States. New England Journal of Medicine 335:716720.
SEER Cancer Statistics Review, 19752002. (2005) (National Cancer InstituteIn Ries L. A. G., Eisner M. P., Kosary C. L. (Eds.), et al. , Bethesda, MD) Available at http://seer.cancer.gov/csr/1975_2002.
Schoenborn C. A. and Danchik K. M. (1980) Health practices among U.S. adults, United States, 1977. Advance Data from Vital and Health Statistics. No. 64(Public Health Service, Hyattsville, MD).
Schoenborn C. A. and Cohen B. H. (1986) Trends in smoking, alcohol consumption, and other health practices among U.S. adults, 1977 and 1983. Advance Data from Vital and Health Statistics. No. 118(Public Health Service, Hyattsville, MD).
Thomas R. M. and Sobin L. H. (1995) Gastointestinal cancer. Cancer 75:154170.[CrossRef][Web of Science][Medline]
U.S. Department of Health and Human Services. (1998) Tobacco Use among U.S. Racial/Ethnic Minority GroupsAfrican Americans, American Indians and Alaska Natives, Asian Americans and Pacific Islanders, and Hispanics: A Report of the Surgeon General. (DHHS, Centers for Disease Control and Prevention, Atlanta, GA).
Visapaa J. P., Gotte K., Benesova M., et al. (2004) Increased cancer risk in heavy drinkers with the alcohol dehydrogenase 1 C*1 allele, possibly due to salivary acetaldehyde. Gut 53:871876.
Yuan J. M., Govindarajan S., Arakawwa K., et al. (2004) Synergism of alcohol, diabetes, and viral hepatitis on the risk of hepatocellular carcinoma in blacks and whites in the U.S. Cancer 101:10091017.[CrossRef][Web of Science][Medline]
Zeka A., Gore R., Kriebel D. (2003) Effects of alcohol and tobacco on aerodigestive cancer risks: a meta-regression analysis. Cancer Causes and Control 14:897906.[CrossRef][Web of Science][Medline]
![]()
CiteULike
Connotea
Del.icio.us What's this?
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||