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ORIGINAL ARTICLE

UNEQUAL BURDEN OF HEAD AND NECK CANCERIN THE UNITED STATES

W. Jarrard Goodwin, MD,1 Giovana R. Thomas, MD,1 Dorothy F. Parker, MHS,2 Debbie Joseph, MD,3

Silvina Levis, MD,4 Elizabeth Franzmann, MD,1 Charles Anello, ScD,5 Jennifer J. Hu, PhD2,6

1 Department of Otolaryngology, University of Miami Sylvester Comprehensive Cancer Center, University ofMiami Miller School of Medicine, Miami, Florida. E-mail: [email protected] University of Miami Sylvester Comprehensive Cancer Center, Division of Cancer Prevention and Control,University of Miami Miller School of Medicine, Miami, Florida3 University of Miami Miller School of Medicine, Miami, Florida4 University of Miami Sylvester Comprehensive Cancer Center, Department of Medicine,and Miami VAMC, University of Miami Miller School of Medicine, Miami, Florida5 University of Miami Sylvester Comprehensive Cancer Center, Division of Biostatistics,University of Miami Miller School of Medicine, Miami, Florida6 University of Miami Sylvester Comprehensive Cancer Center, Department of Epidemiology andPublic Health, University of Miami Miller School of Medicine, Miami, Florida

Accepted 29 May 2007Published online 30 October 2007 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/hed.20710

Abstract: Background. Black Americans are adversely affected

bymany types of malignancies.

Methods. We reviewed data from the National Cancer Insti-

tute’s Surveillance, Epidemiology, and End Results (SEER) pro-

gram to evaluate racial disparities in head and neck cancer inci-

dence, mortality, and survival.

Results. Head and neck cancer incidence is greater in the

black population and peaks at a younger age. The incidence

disparity is decreasing over time and is less for cancers of the

oral cavity/pharynx (OCP) than for cancers of the larynx. The dis-

parity in survival after diagnosis is substantial for both sites and

is increasing over time because of improvement in survival for

the white population, but not for the black population. Some, but

not all, of the survival disparity is due to more advanced stage at

the time of diagnosis within the black population. The age-

adjusted mortality rate for black men is approximately twice the

rate for white men.

Conclusion. Black Americans clearly bear a greater burden

from head and neck cancer. The underlying causes are largely

unknown, but are most likely due to a complex interplay of differ-

ences in access to health care, quality of medical care, biologic/

genetic factors, incidence of comorbid conditions, exposure to

carcinogens, diet, and cultural beliefs. Prospective studies are

needed to define the relative importance of these factors and to

inform intervention strategies. VVC 2007 Wiley Periodicals, Inc.y

Head Neck 30: 358–371, 2008

Keywords: cancer; oral; pharynx; larynx; race

It has become increasingly clear that black Amer-icans and other socioeconomically disadvantagedsegments of the American population areadversely affected by malignancies. First identi-

Correspondence to: W. J. Goodwin

Contract grant sponsor: Sylvester Foundation, The Papanicalaou Corpsfor Cancer Research, The Flight Attendant Medical Research Instituteand Florida Department of Health.

Dr. Levis has reported a financial interest/relationship with Merck as agrant recipient.

VVC 2007 Wiley Periodicals, Inc. yThis article is a US Government workand, as such, is in the public domain in the United States of America.

358 Racial Disparities in Head and Neck Cancer HEAD & NECK—DOI 10.1002/hed March 2008

fied by Henschke et al1 in 1973, the problem hasreceived increasing attention from the NationalCancer Institute (NCI) and the American CancerSociety. Dr. Harold Freeman, Director of the NCI’sCenter to Reduce Health Care Disparities, recentlyreviewed the subject and placed the blame for thisnational tragedy squarely on 3 aspects of U.S.society: poverty, culture, and social injustice.2 Un-fortunately, 3 decades of study have so far hadonly modest positive impact on the problem.

Head and neck cancer refers to those cancersoccurring in the oral cavity, pharynx, and larynx.In the United States, they represent approxi-mately 3% of all cancers diagnosed in males and2% of those in females. The vast majority of thesecancers are of squamous cell type. Incidence ismuch higher in males, but females are catchingup, most likely due to more equal exposure totobacco over the past 40 years. Head and neck can-cer is, after lung cancer, the most devastating ofthose cancers that are directly related to tobaccoexposure. Other known etiological factors includeingestion of alcohol, which produces a synergisticeffect when combined with tobacco exposure,chronic exposure to certain industrial agents, andinfection with specific subtypes of human papil-loma virus. Unfortunately, there is as yet no prac-tical strategy for early detection of head and neckcancer, and the majority of patients present withadvanced disease. The overall cure rate is approx-imately 50%, but when disease is detected andtreated early, the chance of cure is much higher,90% for stage I and 75% for stage II. Because ofthe impact of head and neck cancer on speech,swallowing and appearance, the burden conferredon affected individuals and families is especiallygreat.

Cancer health disparities are best determinedand measured by 3 health statistics: incidence,mortality, and duration of survival following diag-nosis. Swango published a comprehensive over-view of the epidemiology for cancers of the oralcavity and pharynx in the United States from1973 to 1992, using data from the NCI’s Surveil-lance, Epidemiology and End Results (SEER) pro-gram.3 His review showed that: black Americanshad a higher age-adjusted incidence rate whencompared to white Americans; black Americanswere more likely to present with advanced SEERstage of disease; a lower rate of 5-year survival fol-lowing diagnosis for the black population wasseen across all SEER stages; the disparities seenwere greater for males than for females; and dis-parities were not identified for other races.

Most public health professionals and epidemi-ologists have to date focused their attention on the‘‘big 4’’ cancers (lung, colon, breast, and prostate).Encouraged by the NCI, the American Cancer So-ciety (ACS) and the Centers for Disease Controland Prevention (CDC), the development of effec-tive and sustainable programs addressing the dis-parities seen at the major cancer sites has begun.To date, interest in head and neck cancer dispar-ities has been modest and confined mostly to thestudy of oral and pharyngeal cancer in the publichealth programs of dental schools. Personal expe-rience has made most head and neck oncologistsaware of the increased burden head and neck can-cer places on the black population, especially onyoung black men, but little actual data have beenpublished in the journals that serve this field, andconcerned individuals within the field have as yetdone little to intervene.

The purpose of this essay is to summarize themost recent data on disparities seen in head andneck cancer, review what is known regarding thepossible causes of this problem, and identify someof the most promising areas for future study andintervention.

MATERIALS AND METHODS

We reviewed published data from the NCI’sSEER program to examine racial disparities andtrends over time for head and neck cancers, specif-ically cancers of the oral cavity and pharynx(OCP) and cancers of the larynx.4 The SEER pro-gram collects cancer incidence and survival datafrom population-based cancer registries coveringapproximately 26% of the U.S. population. Theincidence trend data we examined are from theSEER 9 registries (Atlanta, Connecticut, Detroit,Hawaii, Iowa, New Mexico, San Francisco–Oak-land, Seattle–Puget Sound, and Utah). Data onstage distribution and 5-year relative survivalare from the SEER 17 areas (SEER 9 plus theAlaska Native Registry, Greater California,Georgia, Kentucky, Louisiana, Los Angeles, SanJose–Monterey, and New Jersey). Mortality ratesare from the National Center for Health Statis-tics (NCHS) public data file for the total U.S., aspublished in the SEER Cancer StatisticsReview.4

The SEER data used in the study is reformat-ted in Tables 1 to 6 and Figures 1 to 6. Currentracial disparities for incidence and mortality weredetermined by comparing age-adjusted rates byrace and sex from the 2000 to 2003 SEER report.

Racial Disparities in Head and Neck Cancer HEAD & NECK—DOI 10.1002/hed March 2008 359

Trends for age-adjusted incidence and mortalitywere examined using data reported for 1975 to2003. Current stage and survival comparisons arefrom the 1996 to 2002 report, the most recent timeperiod published. Trends in survival were estab-lished from data reported for time periods begin-ning in 1975 to 1977 and continuing through themost recent reported period.

To give the reader a sense of the depth of thedata, we report the standard errors of the esti-mates for the age-adjusted incidence and mortal-ity rates and the total counts (number of incidentcases or deaths from which the rate is calculated)

for each race and sex group and all groups com-bined in Tables 1 to 4. To analyze the significanceof the racial disparities identified in age-adjustedincidence and mortality rates, we used the mag-nitude of the difference identified and thereported standard errors to obtain 2-sided p val-ues. For the trends in incidence, mortality, andsurvival, p values are taken directly from theSEER report. References to p values from thepublished data are provided without adjust-ments for multiplicity. Since many statisticalcomparisons are reviewed, the p values should beinterpreted with caution.

FIGURE 1. Oral cavity and pharynx cancers: Age-adjusted incidence rates by race and sex, 1975 to 2003.

FIGURE 2. Larynx cancer: Age-adjusted incidence rates by race and sex, 1975 to 2003.


RESULTS

Incidence.

Oral Cavity and Pharynx. The 2000 to 2003 incidencerates for OCP cancers by sex and race for each agegroup and overall are displayed in Table 1. Of the4 race/sex groups, black males have the highestage-adjusted incidence rate, which is 15% higherthan the rate for white males (18.0 vs 15.7, p <.01). The disparity between white and black menis larger in the under 65 age group. The incidencerate for black men peaks in the 70 to 74 year agegroup, 5 years earlier than that for white men.Incidence rates for females of both races are lower

than for males. Black females have the lowestage-adjusted rate (5.8), but this was not signifi-cantly different from the rate for white females(6.1). As among males, rates for younger blackwomen are higher than for white women (eg, 8.7compared with 5.3 in the 45 to 49 year age group,and 12.0 compared with 8.3 in the 50 to 55 yearage group).

Larynx. Table 2 lists the 2000 to 2003 incidencerates for laryngeal cancer by sex and race, foreach age group and overall. As with OCP cancers,black males have the highest age-adjusted inci-dence rate for larynx cancer. The rate for blackmen is 77% higher than the rate for white men

FIGURE 3. Oral cavity and pharynx cancers: Age-adjusted mortality rates by race and sex, 1975 to 2003.

FIGURE 4. Larynx cancer: Age-adjusted mortality rates by race and sex, 1975 to 2003.


(11.7 vs 6.6, p < .01). The disparity is greatest formen under age 65, where the rate for black malesis twice that seen in white males (6.4 vs 3.2). Age-specific rates peak for both races in the 70 to 74year age group, but differences in incidence ratesare greatest in younger age groups, with rates forblack males from 40 to 59 years of age being morethan twice those for white males. The age-adjustedincidence rate for black females is 43% higherthan that for white females (2.0 vs 1.4, p< .01).

Trends in Incidence.

Oral Cavity and Pharynx. Trends in incidence ratesfor OCP cancers by sex and race, from 1975 to

2003 are shown in Figure 1. Age-adjusted inci-dence rates for OCP cancers have decreased overthe past few decades for all race and sex groupscombined, with an Annual Percent Change (APC)of 21.2% between 1975 and 2003 (p < .05). Thelargest decrease has been among black males,with an APC of 23.2% between 1987 and 2003.The disparity in incidence rates between blackand white males has decreased from 33% in 1987(30.0 compared with 20.2), to a 13% difference in2003. There has been little difference in incidencebetween black andwhite females since 1985.

Larynx. Trends in incidence rates by sex and racefor larynx cancers from 1975 to 2003 are seen in

FIGURE 5. Oral cavity and pharynx cancer: 5-year relative survival rates by race and sex, 1975 to 2002.

FIGURE 6. Larynx cancer: U.S. 5-year relative survival rates by race and sex, 1975 to 2002.


Figure 2. Age-adjusted incidence rates havedecreased more for OCP cancers, with an APC of22.8% for all race/sex groups combined between1975 and 2003 (p < .05). Black males, blackfemales, and white males experienced an APC of23.0% between 1990 and 2003. The disparity inincidence between black males and white maleshas decreased only slightly from 50% in 1990 to44% in 2003. The rate for black females remainsslightly higher than the rate for white females.

Mortality.

Oral Cavity and Pharynx. The 2000 to 2003 age-adjusted mortality rates for OCP cancer by sexand race, for each age group and overall are dis-

played in Table 3. Mortality rates are highest

among black males. The age-adjusted mortality

rate for black men is nearly twice that of white

men (6.8 vs 3.8, p< .01). The rates for black males

are higher than for white males in both the under

age 65 and the 651 age groups. The percentage

difference was highest in the 60 to 64 year age-

group (26.8 for black males vs 11.5 for white

males). The mortality rate for black females is

modestly higher than that for white females (1.7

vs 1.5, p < .01), and again, the difference in rates

was greater in younger age groups.

Larynx. Table 4 lists the 2000 to 2003 mortalityrates for laryngeal cancer by sex and race, overall

Table 1. Oral cavity and pharynx cancers: age-specific and age-adjusted incidence rates by race and sex: U.S., 2000 to 2003.

Selected age groups, y White males Black males White females Black females

45–49 17.2 24.3 5.3 8.7

50–54 28.7 37.3 8.3 12.0

55–59 38.2 54.9 11.8 11.4

60–64 49.3 63.5 17.2 15.0

65–69 56.7 62.8 19.5 18.6

70–74 60.8 65.8 26.3 17.7

75–79 62.4 57.9 29.3 20.6

80–84 60.4 58.3 30.0 22.4

851 64.0 34.1 30.1 19.5

Age less than 65 9.2 12.2 3.2 3.8

Age 651 60.4 58.3 26.1 19.4

Age-adjusted rate 15.7 18.0 6.1 5.8

Total count n 5 16,726 n 5 2034 n 5 7843 n 5 848

Standard error* SE 5 0.12 SE 5 0.42 SE 5 0.07 SE 5 0.20

Note: Source: SEER Cancer Statistics Review 1997–2003 (Tables XX-4, A-1, A-2).Rates per 100,000 age-adjusted to the 2000 U.S. Standard Population.*Standard errors are per 100,000 for age-adjusted rate.

Table 2. Larynx cancer: age-specific and age-adjusted incidence rates by race and sex: U.S., 2000 to 2003.


40–44 1.9 4.2 0.8 1.5

45–49 4.4 10.0 0.9 2.8

50–54 8.9 18.6 2.0 3.6

55–59 15.5 32.2 3.5 6.2

60–64 23.9 44.7 5.4 7.9

65–69 29.6 48.9 7.2 6.5

70–74 33.2 56.6 7.2 8.7

75–79 32.1 54.7 5.6 7.2

80–84 28.6 39.7 4.1 n/a

851 24.3 30.3 2.8 n/a

Age less than 65 3.2 6.4 0.8 1.4

Age 651 30.2 48.5 5.9 6.2


Total count n 5 6892 n 5 1226 n 5 1776 n 5 288


Abbreviation: n/a: rates not available (<16 cases).Note: Source: SEER Cancer Statistics Review 1997 to 2003 (Tables XII-4, A-1, A-2).Rates per 100,000 age-adjusted to the 2000 U.S. Standard Population.*Standard errors are per 100,000 for age-adjusted rate.


and for each age group. The age-adjusted mortal-ity rates are higher for blackmales compared withwhite males (5.1 vs 2.2, p < .01), and for blackfemales compared with white females (0.9 vs 0.5,p < .01). In the 651 age group, the rates are morethan twice as high for black males (24.2 comparedwith 12.1 for whitemales).

Trends in Mortality.

Oral Cavity and Pharynx. Trends in mortality ratesfor OCP cancer by sex and race from 1975 to 2003are shown in Figure 3. Age-adjusted mortalityrates for OCP cancers for all race/sex groups com-bined have decreased in the past several decades,

with an APC of 22.4% (p < .05), compared with a21.2% decrease in incidence. The largest changewas among black females from 1994 to 2003, withan APC of24.5%.

Larynx. Trends in mortality rates for laryngealcancer by sex and race, beginning in 1975 andextending to 2003, are shown in Figure 4. For allrace/sex groups combined, there was a decrease inage-adjusted mortality rates for larynx cancers(22.1% APC from 1992 to 2003). The mortalitydisparity for black versus white males haschanged little over time. The rate for females ofboth races is low and has been relatively stableover this time period.

Table 3. Oral cavity and pharynx cancers: age-specific and age-adjusted mortality rates by race and sex: U.S., 2000 to 2003.


45–49 2.7 6.8 0.8 1.8

50–54 5.1 12.6 1.2 2.2

55–59 8.6 19.6 2.1 3.5

60–64 11.5 26.8 3.5 4.6

65–69 13.6 26.1 4.9 6.3

70–74 16.6 27.5 7.0 6.5

75–79 18.7 24.1 8.9 7.4

80–84 20.3 25.3 10.5 8.8

851 27.1 22.3 15.7 12.0

Age less than 65 1.7 4.1 0.5 0.9

Age 651 18.0 25.4 8.4 7.7


Total count n 5 16,662 n 5 3217 n 5 8682 n 5 1100


Note: Source: SEER Cancer Statistics Review 1997–2003 (Tables XX-4, A-3, A-4).Rates per 100,000 age-adjusted to the 2000 U.S. Standard Population.*Standard errors are per 100,000 for age-adjusted rate.

Table 4. Larynx cancer: age-specific and age-adjusted mortality rates by race and sex: U.S., 2000 to 2003.


40–44 0.4 0.9 0.1 0.3

45–49 1.0 3.2 0.2 0.7

50–54 2.0 6.8 0.4 1.1

55–59 4.0 12.3 0.9 1.9

60–64 6.8 18.2 1.4 2.9

65–69 8.9 19.2 2.2 3.1

70–74 11.2 26.0 2.7 5.0

75–79 13.2 29.5 2.7 4.3

80–84 14.7 26.1 2.6 3.5

851 15.8 20.2 2.2 3.0

Age less than 65 0.8 2.4 0.2 0.4

Age 651 12.1 24.2 2.5 3.9


Total count n 5 9604 n 5 2231 n 5 2604 n 5 553


Note: Source: SEER Cancer Statistics Review 1997 to 2003 (Tables XII-4, A-3, A-4).Rates per 100,000 age-adjusted to the 2000 U.S. Standard Population.*Standard errors are per 100,000 for age-adjusted rate.


Survival after Diagnosis and Stage

at Time of Diagnosis.

Oral Cavity and Pharynx. Table 5 lists stage distribu-tion and related 5-year relative survival rates forOCP cancer by race and sex for 1996 to 2002.Black males and females are diagnosed with moreadvanced disease than are whites. Only 17% ofblack males are diagnosed with localized diseasecompared with 32% of white males. Althoughblack females are more likely to be diagnosed withearly stage disease than black males, their rate ofearly diagnosis is lower than that for whitefemales (31% vs 42%). A higher percentage ofblack males (16% vs 9% for white males) andfemales (13% compared with 8% for whitefemales) present with distant disease (the mostadvanced SEER stage) at the time of diagnosis.

For all stages combined, 5-year relative sur-vival rates for black males and females are lowerthan for whitemales and females. The 5-year rela-tive survival rate for black males is 41% lowerthan the rate for white males (35.6% comparedwith 60.6%). The difference in relative survivalbetween black and white males is observed for all

stages of disease at diagnosis (localized – 63.9% vs82.9%, regional – 32.1% vs 54.2%, and distant –22.6% vs 25.6%). For all stages combined, relativesurvival rates for females of both races are higherthan for males, but the rate for black females(49.1%) is 21% lower than for white females(61.6%).

Larynx. Stage distribution and related 5-year rel-ative survival rates for laryngeal cancer by raceand sex for 1996 to 2002 are seen in Table 6. Simi-larly, black females present with more advancedSEER stage at the time of diagnosis, and the sur-vival disparity is seen across all SEER stages.Overall, black females fare worse than whitefemales, with 44.4% of black females and 60.3%of white females surviving 5 years for all stagescombined.

The 5-year relative survival rate for all stagescombined is 56.4% for black males and 67.3% forwhite males, a difference of 16%. Black malesagain present with more advanced disease thando white males (localized: 35% vs 48%; regional:55% vs 45%; and distant 6% vs 3%), and the dif-ference in relative survival is seen across all

Table 5. Oral and pharynx cancers: stage distribution and 5-year relative survival rates by race and sex: U.S., 1996 to 2002.

Stage at

diagnosis

White males

(n 5 16,629)

Black males

(n 5 2185)

White females

(n 5 7715)

Black females

(n 5 876)

All race/sex

combined

(n 5 30,031)

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Localized 32% 82.9% 17% 63.9% 42% 80.8% 31% 79.7% 33% 81.3%

Regional 53% 54.2% 61% 32.1% 44% 51.3% 52% 39.1% 52% 51.7%

Distant 9% 25.6% 16% 22.6% 8% 29.9% 13% 19.6% 10% 26.4%

Unstaged 5% 48.5% 5% 26.6% 6% 40.5% 5% 38.3% 5% 45.0%

All stages 100% 60.6% 100% 35.6% 100% 61.6% 100% 49.1% 100% 58.8%

Note: Source: SEER Cancer Statistics Review 1997 to 2003 (Tables XX-5).

Table 6. Larynx cancer: stage distribution and 5-year relative survival rates by race and sex: U.S., 1996 to 2002.

Stage at

diagnosis

White males

(n 5 7121)

Black males

(n 5 1291)

White females

(n 5 1826)

Black females

(n 5 349)

All race/gender

combined

(n 5 11,053)

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Stage

distribution

5-year

survival

Localized 48% 86.5% 35% 77.6% 44% 78.1% 36% 64.3% 45% 83.5%

Regional 45% 51.6% 55% 48.7% 48% 48.3% 56% 37.1% 47% 50.4%

Distant 3% 15.6% 6% 11.4% 4% –* 5% 15.5% 4% 13.7%

Unstaged 3% 57.2% 3% 40.1% 4% 37.3% 3% –* 3% 48.9%

All stages 100% 67.3% 100% 56.4% 100% 60.3% 100% 44.4% 100% 64.1%

Note: Source: SEER Cancer Statistics Review 1997 to 2003 (Tables XII-5).*Too few cases to calculate.


stages (localized: 77.6% vs 86.5%; regional: 48.7%vs 51.6%; and distant 11.4% vs 15.6%).

Trends in Survival After Diagnosis.

Oral cavity and pharynx. Trends in relative 5-yearsurvival rates for OCP cancer by sex and race,from 1975 to 2002 are shown in Figure 5. Five-year relative survival rates for all groups com-bined improved significantly from 52.9% in 1975to 1977 to 59.9% in 1996 to 2003 (p < .05). Thetrend is positive for black males (30.2% in 1975–1977 to 35.1% in 1996–2002) and black females(48.9% in 1975–1977 to 51.3% in 1996–2002) overthis time period, but did not reach significance.The improvement in 5-year relative survival ratesfor both white males and females is reported asbeing statistically significant (53.9% to 62.0% formales and 55.8% to 62.7% for females).

Larynx. Trends in relative 5-year survival ratesfor laryngeal cancer by sex and race, from 1975 to2002 are shown in Figure 6. No significantimprovement is seen in the 5-year relative sur-vival rate for larynx cancer for any of the sex/racegroups or for all groups combined. The trend isadverse for black males (from 58.3% to 54.5%)and black females (from 63.5% to 44.3%), stablefor white females (from 61.9% to 61.3%), andweakly positive for white males (from 67.9% to69.1%).

DISCUSSION

All 4 of the race/sex groups seem to be benefitingfrom improved public health measures, since age-adjusted incidence and mortality rates for OPCand larynx cancers are decreasing over time foreach. Age-adjusted incidence peaked for eachgroup between the late 1970s and the mid 1980s,and reached a low point in the most recent SEERtime period available. Yet the data summarizedabove make it abundantly clear that black Ameri-cans bear a greater burden from head and neckcancer, and the disparity is especially striking inthe SEER data for survival following diagnosis,for which the difference is growing over timebecause of improvement for the white Americans,but not for black Americans.

The SEER data used as a primary source inthis study has significant limitations, which inturn limit the conclusions which can be drawn,especially with regard to the specific causes of thedisparities identified. There is a growing body of

literature addressing aspects of the problem,though most studies are retrospective and sufferfrom limitations of their own.

Incidence Disparity. The differences in age-adjustedincidence for OCP cancer in blackmen andwomenas compared to their white counterparts, havedecreased from that described by Swango in 1996,but remain substantial in the age groups less than65 years old. The age-adjusted incidence of laryn-geal cancer in black Americans is more than 60%greater than that seen in white Americans andthe percentage difference has been fairly stableover time. As in OCP cancer, the difference in la-ryngeal cancer incidence between black and whiteAmericans seems to be greatest in the fourth andfifth decades of life. The reason for the greaterincidence disparity in laryngeal cancer isunknown.

The known causes of head and neck cancershould direct inquiry into the reasons for the inci-dence disparity. These include tobacco and alcoholexposure, nutritional factors, certain industrialexposures, poor oral health, and infection withhuman papillomavirus type 16 (HPV 16).5 Ofthese, exposures to tobacco and alcohol have longbeen thought to be the most important. Studieshave repeatedly shown that the risk of head andneck cancer is dose related for each and that thecombination is synergistic.6 Recognition of the im-portance of HPV has been more recent. A recentstudy demonstrated that 50% of cancers of theoropharynx and 36% of oral cancers contain HPVDNA.7 Hereditary factors also play a role. Casecontrol studies of populations of head and neckcancer patients and controls in Brazil8 and PuertoRico9 showed that the relative risk of developinghead and neck cancer was 3.7 and 2.6, respec-tively, if a first degree relative also had head andneck cancer.

Day et al10 studied racial differences in expo-sure to known risk factors for oral cavity cancer in1065 oral cancer patients (871 white and 194black patients) and 1182 control subjects (979white and 203 black Americans). From calculationof population-attributable risks, they concludedthat ‘‘patterns and risks associated with excessalcohol exposure, particularly among currentsmokers, are the most important contributors tothe excess incidence in blacks.’’ They also foundthat ‘‘blacks more often tended to be in socio-de-mographic and medical or dental health catego-ries associated with increased risk,’’ and that ‘‘pro-tective effects provided by higher dietary intake of


fruits and vitamin C were more pronounced forwhites.’’ Others have postulated that increasedrisk may in part be associated with a preferencefor menthol cigarettes among black Americans.11

A growing number of publications have foundan inverse association between vitamin D and itsproxy, sun exposure, and cancer incidence andmortality.12–15 Giovannucci et al,15 reporting astudy of 4286 cancer cases and 2025 relateddeaths in 51,529 male health professionals in theHealth Professions Follow-up Study Cohort,found a statistically significant inverse associa-tion between predicted vitamin D levels andcancer incidence and mortality. An increment inpredicted vitamin D levels of 25 nmol/L was asso-ciated with a 17% reduction in total cancer inci-dence and a 29% reduction in total cancer mortal-ity, and for digestive cancers, a 43% and 45%reduction in incidence and mortality, respectively.Of interest here, the strongest association was forincidence of OCP cancers (RR 5 0.30; 95% CI 50.11–0.81).

Unless an individual is on vitamin supple-ments or regularly consumes fortified dairy prod-ucts, the most common source of vitamin D is der-mal production, which occurs when solar ultravio-let light initiates its synthesis from precursors inthe skin. Daily ingestion of vitamin D by blackAmericans is below that which is recommendedand from 6% to 31% lower than the intake ofwhite Americans of comparable sex and age.16 Itfollows that black Americans might be expected tobe vitamin D deficient, because of their low die-tary intake and pigmented skin. Indeed, datafrom National Health and Nutrition ExaminationSurvey (NHANES) III showed that nationwide,blacks have the lowest vitamin D levels of all eth-nic groups; overall, blackmen have 7.5-fold higherrisk of hypovitaminosis D than white men and2.7-fold higher risk thanHispanic men.17

Finally, differential genetic susceptibility inblacks and whites may play a role in the incidencedisparity, since one hallmark of genetic suscepti-bility for a disease is younger age of onset, as seenin blacks for head and neck cancer. It is wellknown that head and neck cancer occurs througha progression of multiple genetic mutations18 andthat there is a familial tendency to develop thisdisease,8,9 but an inherited gene(s) that conveys ahigher risk has not been identified, let alone stud-ied for differential expression in blacks versuswhites. Yoo et al19 studied DNA from tumor tissueand blood in 18 black and 19 white head and neckcancer patients. They found no significant differ-

ences in microsatellite alterations for chromo-somal arms 1p, 3p, 4q, 9p, 13q, or 17p, but con-clude that this preliminary study should not beconsidered definitive. Since the hallmark of thecarcinogenic process for head and neck cancer isexposure to tobacco and alcohol, and individualsusceptibility to these carcinogens varies widely,many investigators have studied the role of altera-tions in the enzymes that activate or inactivatethese carcinogens in order to identify molecularmarkers of risk. The possibility of differential me-tabolism of tobacco in blacks versus whites is sup-ported by an important study by Caraballo et al,20

which included 665 black subjects and 900 whitesubjects and reported that ‘‘black smokers hadcotinine levels that were substantially higher atall levels of smoking than did white smokers.’’Lazarus and Park21 reviewed a large body of liter-ature reporting the frequency of genetic polymor-phisms in genes coding for many differentenzymes classified into 5 different types of tobaccoand alcohol metabolizing enzymes, and concludedthat these polymorphisms conveyed a small butsignificant increase in risk of head and neck can-cer, that this risk is linked to the level of carcino-gen exposure and may differ between racialgroups. Finally, others have studied differentialmarkers of DNA repair capacity,22 but there areas yet no reports of racial differences in DNArepair capacity in relation to incidence of headand neck cancer. It is difficult to make conclusionsfrom the studies reported thus far, and muchremains to be done.

Survival after Diagnosis and Mortality. The most impor-tant component of the burden negatively impact-ing black Americans is clearly the large disparityin 5-year survival following diagnosis. The goodnews is that overall survival (all races and sexes)has improved for OCP cancer (from 52.9% in1975–1977 to 59.9% in the most recent figures),but unfortunately black Americans have notshared equally in this progress and the gap haswidened (Figure 5). Survival is better for laryn-geal cancer, but has not improved over this timeperiod overall or for any of the race/sex groups,and the disparity burdening black Americansremains substantial (Figure 6).

The degree to which the survival andmortalitydisparities for black Americans are related to pov-erty versus race is incompletely understood. Bachet al synthesized data from 54 articles meetingstrict inclusion criteria (requiring at least 10 blackpatients and 10 white patients, specifying equal


treatment, and adjusting survival by stage) tocompare cancer-specific survival in 189,877 whiteAmericans and 32,004 black Americans with 14different types of cancer. They found that the over-all hazard ratio of death for the black populationcompared with the white population was just1.07, and that black Americans were at signifi-cantly greater risk for cancer-related death atonly 3 sites: breast, uterus, and bladder.23 Theyconcluded that ‘‘only modest cancer-specific sur-vival differences are evident for black patientsand white patients treated comparably for similarstage cancer,’’ and that ‘‘differences in treatment,stage at presentation, and mortality from otherdiseases should represent the primary targets ofresearch and interventions designed to reduce dis-parities in cancer outcomes.’’

Specifically with regard to head and neck can-cer, SEER data shows that a higher percentage ofblack patients present with advanced stage at thetime of diagnosis, and black patients are morelikely to have a higher percentage of cancer of theoropharynx within the OCP grouping, which car-ries a worse prognosis,24 but these differencesaccount for only part of the survival disparity.Other significant causes of the survival disparitymay include: unequal treatment related to lack ofaccess to quality care, difficulty navigating ourcomplex health care system, or even bias; thegreater incidence of other significant chronic dis-eases (comorbidity) seen concurrently in blackpatients diagnosed with cancer; and culturalbeliefs among black patients.

Unequal Detection and Treatment. Review and inter-pretation of tumor registry data by several groupsshows differences in socioeconomic status andtreatment patterns for black as compared to whitehead and neck cancer patients seen and treatedacross broad geographic areas. Arbes et al25 sum-marized data from 7503 patients with OCP cancer(1165 black patients and 6338 white patients) inthe SEER data base who were diagnosed from1988 to 1993. Adjusted for age and geographicarea, the hazard ratio for death from cancer was1.7 for black patients as compared to whitepatients. Of all the covariables studied, adjustingfor the substantial differences seen in socioeco-nomic status caused the greatest reductions in thehazard ratio for OCP cancer death (1.7–1.3 or57%). Further adjustment for stage at time of di-agnosis (greater in black patients) and treatment(black patients less likely to have surgery) to-gether caused a reduction in hazard for OPC can-

cer death from 1.7 to 1.4, and these 2 togetherwith socioeconomic status accounted for a reduc-tion from 1.7 to 1.1. The authors further suggestthat survival differences within SEER stage couldresult partially from residual confounding bystage; that is, black patients might also be reason-ably expected to have more advanced diseasewithin each stage category.

In another study that was, perhaps, even morecarefully done with regard to treatment variables,Shavers et al26 studied patterns of care, socioeco-nomic status, and comorbidity in 471 patientswith head and neck cancer (34.6% black, 47.6%white, and 17.8%Hispanic) selected from 8 SEERregistry sites. Medical data was reabstracted forall of the selected patients from their medicalrecords, the patient’s physician was contacted toconfirm treatment, and socioeconomic status wasobtained from census data. Black patients wereyounger, more likely to be poor and less likely tohave insurance, more likely to present withadvanced disease, less likely to receive cancerdirected treatment (particularly cancer-directedsurgery), and showed more comorbidity. Analysisby tumor site showed that the black patients wereless likely to receive surgery and more likely toreceive radiation therapy for cancer of the oralcavity, and conversely, more likely to receive sur-gery and less likely to receive radiation for cancerof the larynx, choices of therapy for black Ameri-cans that seem less optimal. Black patients werealso less likely to receive treatment within thefirst 4months after diagnosis.

Finally, tumor registry and census data for thestate of Florida also demonstrate a difference instage at diagnosis (black patients are twice aslikely to present with advanced disease), socioeco-nomic status (lower for black patients), and treat-ment (less frequent surgery) that were felt to bethe primary drivers for decreased survival inblack patients with OCP cancer.27

Studies comparing survival of black and whitepatients treated for head and neck cancer with acommon treatment philosophy at 4 large academicinstitutions suggest that survival differences thatpersist despite perceived equal treatment arerelated primarily to other aspects of the patient’smedical care, especially access to care. Mooreet al28 compared 94 black patients and 815 whitepatients with OPC cancer treated at The Univer-sity of Texas M. D. Anderson Cancer Centerbetween 1984 and 1993. The black patients had a5-year survival rate of just 27.6%, while 52% ofwhite patients survived for 5 years after treat-


ment. Black patients were younger, less well offfinancially, and presented with more advanceddisease. Though a smaller percentage of blackpatients were treated with surgery alone, morewere treated with combined therapy, most likelybecause they presented with more advanced dis-ease, and just 2.1% of black patients and 1.2% ofwhite patients did not receive cancer-directedtherapy. Murdock and Gluckman29 compared 54randomly selected black patients with 52 whitepatients treated at the University of Cincinnatibetween 1991 and 1996. Findings were consistentwith those reported from M. D. Anderson. Twiceas many black patients presented with stage IVdisease, and nearly twice as many black patientsdied during the study period.

Roach et al30 compared survival in 190 whiteand 23 black patients treated for laryngeal cancerat the Martinez Veterans Administration MedicalCenter in San Francisco between 1968 and 1988.Black and white patients in this study were simi-lar with regard to age and stage at diagnosis, typeof treatment received, and, most notably, survivalrate. The authors point out that others haveshown a similar lack of racial disparity in survivalfor cancers at other sites (colon and rectum, stom-ach, lung and prostate, but not bladder) forpatients treated within the VA system.31

More recently, Gourin and Podolsky32 reporteda comparison study of 478 black patients and 650white patients treated at a single institution inGeorgia between 1985 and 2002. Compared withwhite patients, black patients were younger, morelikely to be male, less likely to have health insur-ance (8.6% vs 21.7%), more likely to abuse alcohol(88% vs 74%), more likely to present with stageIV disease (66% vs 47%), and more likely to beconsidered inoperable (57% vs 31%). Five-yeardisease-specific survival was 29.3% for blackpatients and 54.7% for white patients. After cor-recting for other variables, a significant effect onsurvival by race was found only for health insur-ance status. They conclude that racial disparitiesin head and neck cancer outcomes are due primar-ily to differences in access to health care.

Comorbidity. There is growing evidence that theprevalence of comorbid disease influences sur-vival after diagnosis in populations of patientspresenting with cancers at other sites. Tamme-magi et al33,34 published well-done studies ofpatients afflicted with breast cancer and lung can-cer, which demonstrated that other chronic dis-eases are more common in black patients and that

this has an adverse impact on both delivery oftreatment and survival. They conclude that ‘‘moreblack breast cancer patients die of competingcauses than of breast cancer.’’33 Comorbid condi-tions are especially important in head and neckcancer overall, since the primary etiologic factors,tobacco and alcohol exposure, also cause othersignificant chronic diseases.35,36 An interestingstudy by Reid et al37 confirmed the negativeimpact of comorbid conditions on survival in agroup of 9386 Medicare patients treated for headand neck cancer between 1985 and 1993. Just 8%of their patients were black, and since the studyhad a different focus, they did not report the inci-dence of comorbidity in black patients as com-pared to white patients. Gourin and Podolsky32

did not find a difference in serious comorbidity inblack patients versus white patients treated forhead and neck cancer. This issue warrants furtherstudy in patients with head and neck cancer.

Cultural Beliefs and Negative Experience with the Health Care

System. Investigators have also reported con-cerns among black patients that reflect both cul-tural beliefs and experience with the U.S. health-care system, and which in turn may have animpact on the treatment that some black patientsaccept and complete. These concerns include thefear of being experimented upon, concern that ex-posure of the cancer to air during surgery mightcause tumor spread, lack of confidence in drugstested primarily in white patients, distrust of themedical profession, and fear of discrimination.38

Disparate levels of trust and satisfaction existwithin ethnic and minority populations, evenwhen controlling for the distribution of individu-als across types of health plans.39 Training physi-cians in cultural competence and developing out-reach programs directed at addressing disparatebeliefs and attitudes may help address race-related disparities in clinical outcome due to theseissues.

Priorities for Study and Intervention. The SEER dataused as the primary source for this review, and theretrospective studies discussed above all have lim-itations and serve primarily to inform the direc-tion of future research. Well-designed prospectivestudies are needed to provide definitive answers.What are the important questions identified bythis review? Our views follow, and we also want torecognize that the importance and complexity ofthe problem may warrant comprehensive reviewby impaneling a consensus conference of experts.


Race Versus Poverty. Are the disparities seen inhead and neck cancer due more to race or to pov-erty? This is clearly one of the most fundamentalquestions. Much of the literature reviewed abovesupports a commonly held view that equal careleads to equal outcomes regardless of race. Butare there racial genetic differences that predictrisk for head and neck cancer development andprogression?40,41 Studies to answer this questionare at the top of our priority list. Investigation ofpotential racial differences should be included infuture studies of molecular and genetic predictorsof outcomes for head and neck cancer.

Stage at Diagnosis. More advanced stage at thetime of diagnosis within the black population is animportant component of the disparity in survivalafter diagnosis. Possible explanations include alack of access to high-quality health and dentalservices, less widespread knowledge about dangersignals, and more aggressive variants of disease.We need to know more about the relative impor-tance of each. Sankaranarayanan et al42 recentlydemonstrated that visual screening of the oralcavity reduced oral cavity cancer mortality in ahigh-risk population in India. Can we develop aneffective and practical method of community-based screening for head and neck cancer inunderserved minority populations in the UnitedStates?

Lifestyle. In addition to their role in the develop-ment of head and neck cancer, continued use oftobacco and alcohol after diagnosis has a negativeimpact on survival. Can we do better with tobaccoand alcohol control in young black Americans?Nutritional factors are also likely to be relevanthere. Is relative deficiency of vitamin D and/orother micronutrients an important cause of headand neck cancer development and/or progressionin black Americans?

Comorbidity. Head and neck cancer patients areprone to other significant medical problems. Whatis the impact of comorbid conditions on the sur-vival disparity for head and neck cancer? This hasbeen studied for other cancer sites, but little isknownwith regard to head and neck cancer.

Navigation. The diagnosis and treatment of headand neck cancer is rigorous and difficult to com-plete without the support of family, friends, or anassigned advocate. Can we develop effective navi-gation programs for support of minority patients

undergoing diagnosis and therapy for head andneck cancer?

CONCLUSION

Black Americans suffer disproportionately fromhead and neck cancer. There is a growing body ofknowledge to inform additional research. Well-designed prospective studies are needed to iden-tify the relative importance of the many differentpossible causes of head and neck cancer dispar-ities, and in turn to inform intervention strat-egies. Eliminating the disparities in head andneck cancer incidence, survival, and mortalitywould save many lives and lessen the sufferingfrom this devastating disease.

Acknowledgments. The authors wish tothank Rita Soza, PhD., formerly of the Universityof Miami Sylvester Comprehensive Cancer Cen-ter, for her help with data extraction and analysis.

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