Cancer Incidence in the Western United States: Ethnic Differences Jane H. Hu, PhD, and Jack E. White, MD Washington, DC
Incidence rates of selected cancer sites reported by the California Tumor Registry and the New Mexico Tumor Registry are analyzed to study ethnic differences in cancer in the United States. The white majority population shows high incidence of lung and breast cancers. Black males show the highest prostatic cancer rate. Data also confirm the unusually high incidence of nasopharyngeal cancer and low prostatic cancer rates among Chinese males. The Japanese have the highest stomach cancer incidence among all the ethnic groups analyzed. A comparison with the cancer incidence in the same ethnic groups in their native countries reveals the impact of environmental or cultural changes on lung, breast, and stomach cancers, and a possible genetic influence on the high incidence of nasopharyngeal cancer among the Chinese population in the United States. Incidence rates of various types of cancers are the combined results of environmental impacts and the genetic factors of the individuals involved. The US population is a mixture of all races, their characteristics and cultural heritages. To understand cancer problems in the United States it is important to analyze the cancer problems and their differences among various ethnic groups. The present study is to summarize information concerning ethnic differences in cancer in the United States. Cancer problems of different US ethnic groups are compared with those in their native countries to reveal the influence of environmental and cultural changes on cancer.
Methods Cancer incidence data collected and reported by the California Tumor Registry (CTR) and the New Mexico Tumor Registry were compared and analyzed according to major ethnic groups. Cancer incidence data utilized in these studies were collected by surFrom the Department of Oncology, Howard University Cancer Center, Howard university, Washington, DC. Requests for reprints should be addressed to Dr. Jane H. Hu, 9909 Fleming Avenue, Bethesda, MD 20014.
vey or by special ongoing incidence reporting systems. 1-3 The data collected by the California Tumor Registry, a section of the newly organized San Francisco Bay Area Resource for Cancer Epidemiology, and by the New Mexico Tumor Registry were reported by racial groups (distinct ethnic differences are characteristic of the populations of these areas). The 1969-1971 data collected by the California Tumor Registry was part of the Third National Cancer Survey. Information on 1972 diagnoses was collected by the CTR's ongoing Cancer Incidence System, and reported by racial group in the San Francisco Bay Area and in Alameda County, California. The major ethnic groups in these areas were classified as white, Negro, Chinese, and Japanese. The cancer information collected by the New Mexico Tumor Registry from 1969-1972 and analyzed by the New Mexico Department of Vital Statistics, was also reported according to major racial groups in this, area: white, Spanish, American Indian, and Negro. Cancer incidence data for selected cancer sites of various US racial groups in the above areas were also compared with cancer statistics of the same races in their native countries. Age-adjusted mortality rates by selected cancer sites were used as an indication of the cancer
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 71, NO. 4, 1979
problems of natives of various countries.4
Cancer Incidence Rates of the Major Ethnic Groups in the San Francisco-Oakland Area The average annual age-adjusted cancer incidence rates expressed in the total number of cases per 100,000 population among major ethnic groups (white, Negro, Chinese, Japanese) in the San Francisco-Oakland area are shown in Figure 1. 1 Cancer incidence rates by selected cancer sites also were compared among the major ethnic groups of this area (Table 1). The original data were collected by the California Tumor Registry from 1969 to 1972.1 Selected cancer sites for comparison were nasopharynx, stomach, colon and rectum, liver, lung and bronchus, breast (female), corpus uteri (female), prostate, and skin. Among the majority white population, cancers of the lung and bronchus (41.2 per 100,000 persons), colon and rectum (43.6 per 100,000), and prostate (50.1 per 100,000) showed the highest average annual age-adjusted cancer incidence rates for males, breast cancer (87.3 per 100,000) and, to a lesser extent, uterine cancer (31.5 per 100,000) showed the highest incidence rates for females. Compared with other racial groups (Negro, Chinese, and Japanese), the white population had the highest colon and rectal cancer incidence rates, and the highest breast cancer and uterine cancer incidence rates. The incidence rate of melanoma of skin was also relatively higher among the white population than in the Negro, Chinese or Japanese populations. For the purpose of comparison, the cancer incidence rates for other ethnic groups were expressed in percentages of the white majority cancer incidence rates (Table 1). The black population showed high incidence rates of cancer of the pros345
tate (82.9 per 100,000), of the lung and bronchus (47.5 per 100,000), of the colon and rectum (35.9 per 100,000) and of the breast (female, 58.7 per 100,000). Incidence rates of prostate cancer and lung and bronchial cancers in the black population were the highest of all racial groups in this area. Chinese living in the San Francisco Bay area also showed high incidence rates of lung and bronchial cancers White
311.6
Negro
302.5
251.8
Chinese Japanese
167.6
_ 0 150
200
250
300
350
Rates Per 100,000 Population
Figure 1. Average annual ageadjusted cancer incidence rates of major ethnic groups in the San Francisco-Oakland area (19691972).
(45.0 per 100,000), breast cancer (45.1 per 100,000), and colon and rectal cancers-(34.1 per 100,000), as did US white and black populations. Distinct characteristics of cancer problems among the Chinese population were the high rates of liver cancers (14.5 per 100,000; 630.4 percent incidence rate of the white population), and nasopharyngeal cancer (15.3 per 100,000; 255 percent incidence rate of the white population). The incidence rate of prostate cancer (18.1 per 100,000) was lower among Chinese males than in the other racial groups of this area. Japanese immigrants to this area had the lowest total cancer incidence rate (167.6 per 100,000), approximately one half of the cancer incidence rates of the white population (311.6 per 100,000) or the black population (302.5 per 100,000). The Japanese population had the highest stomach cancer rate of the studied groups. This is consistent with findings in other parts of the world. 14
Cancer Patterns of Major Ethnic Groups in Alameda County, California The cancer incidence in most major sites showed a general increase in Alameda County, California, during the period 1960-1969. The increase in the incidence of lung cancer, in both males and females, and in breast cancer in females was significant. The high incidence of prostatic cancer among the black population and the white population was noteworthy. The incidence of stomach cancer was relatively low, especially among area Japanese and Chinese.2 Table 2 shows the age-adjusted cancer incidence rates of selected cancer sites among the major ethnic groups in Alameda County, California, during the period 1960-1969. For the purpose of comparison, the data were expressed as percentages of the cancer
Table 1. Average Annual Age-Adjusted Cancer Incidence Rates (Site by Race) and Percentages in Comparison with US Whites, San Francisco-Oakland Standard Metropolitan Statistical Area, 1969-1972 Primary Site Nasopharynx Stomach Colon and Rectum Liver Lung and Bronchus Breast (Female) Corpus uteri (Female) Prostate Melanoma of Skin
White
%
Black
%
Chinese
%
Japanese
%
0.6 9.7 43.6 2.3 41.2 87.3 31.5 50.1 6.3
100 100 100 100 100 100 100 100 100
0.8 15.5 35.9 3.4 47.5 58.7 15.0 82.9 0.4
133.3 159.8 82.34 147.8 115.3 67.24 47.62 165.5 6.35
15.3 11.7 34.1 14.5 45.0 45.1 16.7 18.1 0.3
255.0 120.6 78.2 630.4 109.2 51.66 53.02 36.13 4.76
0.0 23.5 29.6 1.0 12.7 38.2 12.1 23.7 0.0
0.0 242.3 55.2 43.5 30.8 43.75 38.41 47.3 0.0
Table 2. Age-Adjusted Cancer Incidence Rates (Selective Sites by Sex and Race) and Percentages in Comparison with US Whites, Alameda County, California 1960-1969
White
346
Black
Chinese
%
Japanese % Rate
%
Rate
297.9 0.6 22.9 28.0 57.0 80.4
103.6 75 157.9 64.97 105.4 181.1
239.3 15.0 9.9 46.7 50.4 17.0
83.23 18.75 68.28 108.4 93.16 38.29
192.0 0.0 50.4 28.8 19.8 16.5
66.78 0.0 347.6 66.82 36.60 37.16
227.1 8.2 29.1 11.8 52.0 17.5 34.8
87.75 107.9 80.6 106.3 70.5 78.83 183.2
238.4 9.3 28.0 18.7 73.2 14.3 19.2
92.12 122.4 77.56 168.5 99.19 64.41 101.1
264.4 56.6 40.8 12.4 43.9 12.6 22.2
102.2 744.7 113.0 117.1 59.49 56.76 116.8
Primary Site
Rate
%
Rate
Male All Sites Nasopharynx Stomach Colon and Rectum Bronchus and Lung Prostate
287.5 0.8 14.5 43.1 54.1 44.4
100 100 100 100 100 100
Female All Sites Stomach Colon and Rectum Bronchus and Lung Breast Corpus Uteri Cervix Uteri
258.8 7.6 36.1 11.1 73.8 22.2 19.0
100 100 100 100 100 100 100
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Table 3. The Most Common Cancers in US Groups Studied Expressed as Percentages of All Cancer Sites by Ethnic Groups and Sex as Compared to the Same Groups: Native Countries (Except Skin Cancers, Leukemia, and Lymphoma) Ethnic Groups by Sex
Cancer Sites
United States New Mexico, 1969-1972 Alameda County, California, 1960-1969
England and Wales (% Death Rates, 1968-1969)
White Male
Bronchus and Lung Prostate Colon and Rectum
21.2% 4 18.6% 4 12.9%
18.8% 4 15.4% 4 14.99%
38.63% 6.37% 11.62%
Breast Colon and Rectum Uterus Bronchus and Lung
30.3% 4 14.2% 7.8% 5.7%
28.52% 4 13.95% 8.58% 4.29%
21.47% 14.98% 8.28% 9.83%
White Females
Mexico (% Death Rates, 1968-1969)
Spanish-speaking Males Prostate Stomach Bronchus and Lungs Colon and Rectum
22.2% 4 11.5% 10.4% 9.5% 4
No Data
8.67% 19.35% 13.66% 5.03%
Breast Cervix Colon and Rectum Stomach
18.0% 4 12.1% 8.7% 4 7.2% 4
No Data
6.06% 26.37% (uterus) 4.80% 12.98%
Spanish-speaking Females
Dominican Republic
(% Death Rates, 1968-1969) Black Males Prostate Bronchus and Lung Stomach Colon and Rectum
20.6% 4 20.6% 4 7.6% 4 6.5%
26.99% 4 19.13% 4 7.69% 4 9.40%
10.37% 10.62% 12.56% 8.99%
Breast Colon and Rectum Uterus Stomach
19.4% 4 19.4% T 6.9% 4 5.6%
22.89% 4 12.81% t 15.32% 4 3.61%
8.52% 8.57% 22.76% .38%
Black Females
Taiwan (% Death Rates, 1968-1969)
San FranciscoOakland 1969-1972 Chinese (Males and Females) Breast (Female) Lung and Bronchus Colon and Rectum Uterus (Female) Stomach
17.91% 17.87% 13.34% 7.59% 4.65%
4 4 4 4
30.70% 14.47% 15.63% 4.02% 4.02%
4 4 4 4
San FranciscoOakland 1969-1972
Japanese (Males
2.17% 9.75% 8.21% 8.33% 19.88% Japan (% Death Rates, 1968-1969)
and Females)
Breast (Female) Colon and Rectum Prostate Stomach Lung and Bronchus
22.79% 4 17.66% 4
16.60% 4 15.63% 4
14.14% 4 14.02% 4 7.58%
3.45% 4 22.40% 4 6.74%
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1.70% 6.97% 0.87% 42.61% 8.56%
347
incidence rates among the white population. Consistent with findings of the San Francisco-Oakland Area report, white and black populations showed higher rates of cancer incidence in all sites (white, 287.5 per 100,000; black, 297.9 per 100,000). Japanese showed the lowest cancer incidence rate in all sites (192.0 per 100,000). Consistent with the report from the San Francisco area, the white majority population had high incidences of both lung and breast cancers. Black males showed the highest prostatic cancer rate. The data also confirmed the unusually high incidence of nasopharyngeal cancer and low prostatic cancer rate among Chinese males. Japanese had the highest stomach cancer incidence among all ethnic groups analyzed.
A Comparison of Cancer Incidence in Major US Ethnic Groups With the Same Groups in Native Countries Table 3 shows the incidence of major cancers expressed as percentages of all major cancer sites by racial groups and sex in the Western United States, as compared to the same racial groups in their native countries.24 The US white population showed a decreased problem of lung and bronchial cancer as compared to the white populations in England and Wales. The US incidence of prostatic cancer was much lower than the death rate for prostatic cancer in white British. Breast cancer incidence was slightly elevated for white females in the US. For the Spanish population in New Mexico, 1969-1972, the prostatic cancer problem was more severe than for native Mexicans. Stomach cancer incidence declined for both males and females. Breast cancer in Spanish females was increased. In US blacks, as compared to the native black population of the Dominican Republic, prostate and lung cancers were increased. Stomach cancer incidence was considerably decreased among males. Breast, colon, and rectal cancers were markedly elevated and uterine cancer was reduced among females. 348
For the US Chinese population as compared to Chinese natives on Taiwan, breast cancer (female), lung and bronchial cancer, and colon and rectal cancers were all increased. The incidence of stomach cancer among the Chinese Americans was considerably reduced. As in the Chinese, the trend of changes in cancer problems among the Japanese population in the United States was observed. An increased incidence of cancer of the breast (female), colon, rectum, and prostate and a marked decrease in stomach cancer incidence were rated.
Discussion A comparison of several regional studies of the ethnic differences in cancer incidence in the United States demonstrates some consistent and interesting observations. According to reports submitted by the Advisory Committee to the Surgeon General of the Public Health Service, the primary risk factor for lung and bronchial cancer is cigarette smoking.5-7 Air pollution is also associated with increased lung cancer incidence, other causes are asbestos fibers and radon in mining and industry. As smoking, air, and industrial pollution problems have increased in the United States, the incidence of lung cancer has shown a general trend of escalation in recent years. The breast cancer incidence of all ethnic groups analyzed showed a steady trend of increase among white, black, Chinese, and Japanese females. For example, a rising incidence of breast cancer among Japanese women in California was documented. 1.2.8,9 Data for the native Japanese population were reported by Segi in 1970.8 The incidence of breast cancer increased from 14.4 percent of all cancers among native Japanese women to 36.2 percent of all cancers among CaliforRian-Japanese women under age 55.9 The rising incidence of breast cancer among all ethnic groups may be explained on the basis of cultural characteristics in the United States, eg, the delayed age of first delivery, high fat consumption, and socioeconomical fac-
tors.10O
The unusually high incidence of liver cancer and nasopharyngeal cancer among Chinese males has been investigated extensively.11-14 Genetic factors may be important, since both US Chinese and native Chinese in Taiwan showed similar cancer characteristics. The high incidence of stomach cancer among the Japanese population may be related to their cultural heritage as well as to genetic factors. A reduced stomach cancer incidence was observed among the US Japanese population in California, as compared to the exceedingly high stomach cancer death rate of the native Japanese population in Japan.1'2'9 Similarly, a reduction of stomach cancer incidence was also observed among the Spanish population, and the Chinese population in the western United States. Cultural changes, especially related to dietary habits, may contribute to the decline of stomach cancer incidence.
Literature Cited 1. The San Francisco Bay Area Resource for Cancer Epidemiolopy, vol 3, no. 1. Berkeley, Calif, State of California, Department of Public Health, 1973 2. Arellano MG, Linden G, Dunn JE: Cancer patterns in Alameda County, California. Br J Cancer 23:473-482, 1972 3. Buechley RW, Howard CA, Kutvirt DM, et al: Cancer Trends Among Ethnic Groups in New Mexico. Monterrey, Mexico, US-Mexico Border Public Health Association, 1974 4. Cancer statistics. Age-adjusted death rates per 100,000 population for selected cancer sites for 40 countries. World Health Statistics Annual, 1968-69. CA 25(1):8-21, 1975 5. Smoking and Health. In Advisory Committee to the Surgeon General of the Public Health Service (Washington DC): Report. PHS Publication No. 1103, 1964 , Supplemental Report, 1967 6. , Supplemental Report, 1972 7. 8. Segi M: Japan, Miyagi Prefecture. In Dali R, Muir CS, Waterhouse JAH: Cancer Incidence in Five Continents, vol 3. Geneva, UICC, 1970 9. San Francisco Bay Area Resource for Cancer Epidemiology: Japanese Cancer Project: Project Record. Berkeley, Calif, State of California, Department of Public Health, 1970 10. Zippin C, Petrokis NL: Identification of high risk groups in breast cancer. Cancer 28:1381-1387, 1971 11. Buell P: Nasopharynx cancer in Chinese of California. Br J Cancer 19:459-470, 1965 12. Clifford P: A review on the epidemiology of nasopharyngeal carcinoma. Int J Cancer 5:287-309, 1970 13. Muir CS: Nasopharyngeal carcinoma; A historical vignette. In Muir CS, Shanmagaratnam K: Cancer of the Nasopharynx. Geneva, UICC Monograph Series, 1967, p 47 14. Zippin C, Tekawa I, Bragg K, et al: Studies on heredity and environment in cancer of the nasopharynx. J Natl Cancer Inst 29:483490, 1962
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 71, NO. 4, 1979
Incidence rates of selected cancer sites reported by the California Tumor Registry and the New Mexico Tumor Registry are analyzed to study ethnic differences in cancer in the United States. The white majority population shows high incidence of lung and breast cancers. Black males show the highest prostatic cancer rate. Data also confirm the unusually high incidence of nasopharyngeal cancer and low prostatic cancer rates among Chinese males. The Japanese have the highest stomach cancer incidence among all the ethnic groups analyzed. A comparison with the cancer incidence in the same ethnic groups in their native countries reveals the impact of environmental or cultural changes on lung, breast, and stomach cancers, and a possible genetic influence on the high incidence of nasopharyngeal cancer among the Chinese population in the United States. Incidence rates of various types of cancers are the combined results of environmental impacts and the genetic factors of the individuals involved. The US population is a mixture of all races, their characteristics and cultural heritages. To understand cancer problems in the United States it is important to analyze the cancer problems and their differences among various ethnic groups. The present study is to summarize information concerning ethnic differences in cancer in the United States. Cancer problems of different US ethnic groups are compared with those in their native countries to reveal the influence of environmental and cultural changes on cancer.
Methods Cancer incidence data collected and reported by the California Tumor Registry (CTR) and the New Mexico Tumor Registry were compared and analyzed according to major ethnic groups. Cancer incidence data utilized in these studies were collected by surFrom the Department of Oncology, Howard University Cancer Center, Howard university, Washington, DC. Requests for reprints should be addressed to Dr. Jane H. Hu, 9909 Fleming Avenue, Bethesda, MD 20014.
vey or by special ongoing incidence reporting systems. 1-3 The data collected by the California Tumor Registry, a section of the newly organized San Francisco Bay Area Resource for Cancer Epidemiology, and by the New Mexico Tumor Registry were reported by racial groups (distinct ethnic differences are characteristic of the populations of these areas). The 1969-1971 data collected by the California Tumor Registry was part of the Third National Cancer Survey. Information on 1972 diagnoses was collected by the CTR's ongoing Cancer Incidence System, and reported by racial group in the San Francisco Bay Area and in Alameda County, California. The major ethnic groups in these areas were classified as white, Negro, Chinese, and Japanese. The cancer information collected by the New Mexico Tumor Registry from 1969-1972 and analyzed by the New Mexico Department of Vital Statistics, was also reported according to major racial groups in this, area: white, Spanish, American Indian, and Negro. Cancer incidence data for selected cancer sites of various US racial groups in the above areas were also compared with cancer statistics of the same races in their native countries. Age-adjusted mortality rates by selected cancer sites were used as an indication of the cancer
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 71, NO. 4, 1979
problems of natives of various countries.4
Cancer Incidence Rates of the Major Ethnic Groups in the San Francisco-Oakland Area The average annual age-adjusted cancer incidence rates expressed in the total number of cases per 100,000 population among major ethnic groups (white, Negro, Chinese, Japanese) in the San Francisco-Oakland area are shown in Figure 1. 1 Cancer incidence rates by selected cancer sites also were compared among the major ethnic groups of this area (Table 1). The original data were collected by the California Tumor Registry from 1969 to 1972.1 Selected cancer sites for comparison were nasopharynx, stomach, colon and rectum, liver, lung and bronchus, breast (female), corpus uteri (female), prostate, and skin. Among the majority white population, cancers of the lung and bronchus (41.2 per 100,000 persons), colon and rectum (43.6 per 100,000), and prostate (50.1 per 100,000) showed the highest average annual age-adjusted cancer incidence rates for males, breast cancer (87.3 per 100,000) and, to a lesser extent, uterine cancer (31.5 per 100,000) showed the highest incidence rates for females. Compared with other racial groups (Negro, Chinese, and Japanese), the white population had the highest colon and rectal cancer incidence rates, and the highest breast cancer and uterine cancer incidence rates. The incidence rate of melanoma of skin was also relatively higher among the white population than in the Negro, Chinese or Japanese populations. For the purpose of comparison, the cancer incidence rates for other ethnic groups were expressed in percentages of the white majority cancer incidence rates (Table 1). The black population showed high incidence rates of cancer of the pros345
tate (82.9 per 100,000), of the lung and bronchus (47.5 per 100,000), of the colon and rectum (35.9 per 100,000) and of the breast (female, 58.7 per 100,000). Incidence rates of prostate cancer and lung and bronchial cancers in the black population were the highest of all racial groups in this area. Chinese living in the San Francisco Bay area also showed high incidence rates of lung and bronchial cancers White
311.6
Negro
302.5
251.8
Chinese Japanese
167.6
_ 0 150
200
250
300
350
Rates Per 100,000 Population
Figure 1. Average annual ageadjusted cancer incidence rates of major ethnic groups in the San Francisco-Oakland area (19691972).
(45.0 per 100,000), breast cancer (45.1 per 100,000), and colon and rectal cancers-(34.1 per 100,000), as did US white and black populations. Distinct characteristics of cancer problems among the Chinese population were the high rates of liver cancers (14.5 per 100,000; 630.4 percent incidence rate of the white population), and nasopharyngeal cancer (15.3 per 100,000; 255 percent incidence rate of the white population). The incidence rate of prostate cancer (18.1 per 100,000) was lower among Chinese males than in the other racial groups of this area. Japanese immigrants to this area had the lowest total cancer incidence rate (167.6 per 100,000), approximately one half of the cancer incidence rates of the white population (311.6 per 100,000) or the black population (302.5 per 100,000). The Japanese population had the highest stomach cancer rate of the studied groups. This is consistent with findings in other parts of the world. 14
Cancer Patterns of Major Ethnic Groups in Alameda County, California The cancer incidence in most major sites showed a general increase in Alameda County, California, during the period 1960-1969. The increase in the incidence of lung cancer, in both males and females, and in breast cancer in females was significant. The high incidence of prostatic cancer among the black population and the white population was noteworthy. The incidence of stomach cancer was relatively low, especially among area Japanese and Chinese.2 Table 2 shows the age-adjusted cancer incidence rates of selected cancer sites among the major ethnic groups in Alameda County, California, during the period 1960-1969. For the purpose of comparison, the data were expressed as percentages of the cancer
Table 1. Average Annual Age-Adjusted Cancer Incidence Rates (Site by Race) and Percentages in Comparison with US Whites, San Francisco-Oakland Standard Metropolitan Statistical Area, 1969-1972 Primary Site Nasopharynx Stomach Colon and Rectum Liver Lung and Bronchus Breast (Female) Corpus uteri (Female) Prostate Melanoma of Skin
White
%
Black
%
Chinese
%
Japanese
%
0.6 9.7 43.6 2.3 41.2 87.3 31.5 50.1 6.3
100 100 100 100 100 100 100 100 100
0.8 15.5 35.9 3.4 47.5 58.7 15.0 82.9 0.4
133.3 159.8 82.34 147.8 115.3 67.24 47.62 165.5 6.35
15.3 11.7 34.1 14.5 45.0 45.1 16.7 18.1 0.3
255.0 120.6 78.2 630.4 109.2 51.66 53.02 36.13 4.76
0.0 23.5 29.6 1.0 12.7 38.2 12.1 23.7 0.0
0.0 242.3 55.2 43.5 30.8 43.75 38.41 47.3 0.0
Table 2. Age-Adjusted Cancer Incidence Rates (Selective Sites by Sex and Race) and Percentages in Comparison with US Whites, Alameda County, California 1960-1969
White
346
Black
Chinese
%
Japanese % Rate
%
Rate
297.9 0.6 22.9 28.0 57.0 80.4
103.6 75 157.9 64.97 105.4 181.1
239.3 15.0 9.9 46.7 50.4 17.0
83.23 18.75 68.28 108.4 93.16 38.29
192.0 0.0 50.4 28.8 19.8 16.5
66.78 0.0 347.6 66.82 36.60 37.16
227.1 8.2 29.1 11.8 52.0 17.5 34.8
87.75 107.9 80.6 106.3 70.5 78.83 183.2
238.4 9.3 28.0 18.7 73.2 14.3 19.2
92.12 122.4 77.56 168.5 99.19 64.41 101.1
264.4 56.6 40.8 12.4 43.9 12.6 22.2
102.2 744.7 113.0 117.1 59.49 56.76 116.8
Primary Site
Rate
%
Rate
Male All Sites Nasopharynx Stomach Colon and Rectum Bronchus and Lung Prostate
287.5 0.8 14.5 43.1 54.1 44.4
100 100 100 100 100 100
Female All Sites Stomach Colon and Rectum Bronchus and Lung Breast Corpus Uteri Cervix Uteri
258.8 7.6 36.1 11.1 73.8 22.2 19.0
100 100 100 100 100 100 100
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Table 3. The Most Common Cancers in US Groups Studied Expressed as Percentages of All Cancer Sites by Ethnic Groups and Sex as Compared to the Same Groups: Native Countries (Except Skin Cancers, Leukemia, and Lymphoma) Ethnic Groups by Sex
Cancer Sites
United States New Mexico, 1969-1972 Alameda County, California, 1960-1969
England and Wales (% Death Rates, 1968-1969)
White Male
Bronchus and Lung Prostate Colon and Rectum
21.2% 4 18.6% 4 12.9%
18.8% 4 15.4% 4 14.99%
38.63% 6.37% 11.62%
Breast Colon and Rectum Uterus Bronchus and Lung
30.3% 4 14.2% 7.8% 5.7%
28.52% 4 13.95% 8.58% 4.29%
21.47% 14.98% 8.28% 9.83%
White Females
Mexico (% Death Rates, 1968-1969)
Spanish-speaking Males Prostate Stomach Bronchus and Lungs Colon and Rectum
22.2% 4 11.5% 10.4% 9.5% 4
No Data
8.67% 19.35% 13.66% 5.03%
Breast Cervix Colon and Rectum Stomach
18.0% 4 12.1% 8.7% 4 7.2% 4
No Data
6.06% 26.37% (uterus) 4.80% 12.98%
Spanish-speaking Females
Dominican Republic
(% Death Rates, 1968-1969) Black Males Prostate Bronchus and Lung Stomach Colon and Rectum
20.6% 4 20.6% 4 7.6% 4 6.5%
26.99% 4 19.13% 4 7.69% 4 9.40%
10.37% 10.62% 12.56% 8.99%
Breast Colon and Rectum Uterus Stomach
19.4% 4 19.4% T 6.9% 4 5.6%
22.89% 4 12.81% t 15.32% 4 3.61%
8.52% 8.57% 22.76% .38%
Black Females
Taiwan (% Death Rates, 1968-1969)
San FranciscoOakland 1969-1972 Chinese (Males and Females) Breast (Female) Lung and Bronchus Colon and Rectum Uterus (Female) Stomach
17.91% 17.87% 13.34% 7.59% 4.65%
4 4 4 4
30.70% 14.47% 15.63% 4.02% 4.02%
4 4 4 4
San FranciscoOakland 1969-1972
Japanese (Males
2.17% 9.75% 8.21% 8.33% 19.88% Japan (% Death Rates, 1968-1969)
and Females)
Breast (Female) Colon and Rectum Prostate Stomach Lung and Bronchus
22.79% 4 17.66% 4
16.60% 4 15.63% 4
14.14% 4 14.02% 4 7.58%
3.45% 4 22.40% 4 6.74%
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1.70% 6.97% 0.87% 42.61% 8.56%
347
incidence rates among the white population. Consistent with findings of the San Francisco-Oakland Area report, white and black populations showed higher rates of cancer incidence in all sites (white, 287.5 per 100,000; black, 297.9 per 100,000). Japanese showed the lowest cancer incidence rate in all sites (192.0 per 100,000). Consistent with the report from the San Francisco area, the white majority population had high incidences of both lung and breast cancers. Black males showed the highest prostatic cancer rate. The data also confirmed the unusually high incidence of nasopharyngeal cancer and low prostatic cancer rate among Chinese males. Japanese had the highest stomach cancer incidence among all ethnic groups analyzed.
A Comparison of Cancer Incidence in Major US Ethnic Groups With the Same Groups in Native Countries Table 3 shows the incidence of major cancers expressed as percentages of all major cancer sites by racial groups and sex in the Western United States, as compared to the same racial groups in their native countries.24 The US white population showed a decreased problem of lung and bronchial cancer as compared to the white populations in England and Wales. The US incidence of prostatic cancer was much lower than the death rate for prostatic cancer in white British. Breast cancer incidence was slightly elevated for white females in the US. For the Spanish population in New Mexico, 1969-1972, the prostatic cancer problem was more severe than for native Mexicans. Stomach cancer incidence declined for both males and females. Breast cancer in Spanish females was increased. In US blacks, as compared to the native black population of the Dominican Republic, prostate and lung cancers were increased. Stomach cancer incidence was considerably decreased among males. Breast, colon, and rectal cancers were markedly elevated and uterine cancer was reduced among females. 348
For the US Chinese population as compared to Chinese natives on Taiwan, breast cancer (female), lung and bronchial cancer, and colon and rectal cancers were all increased. The incidence of stomach cancer among the Chinese Americans was considerably reduced. As in the Chinese, the trend of changes in cancer problems among the Japanese population in the United States was observed. An increased incidence of cancer of the breast (female), colon, rectum, and prostate and a marked decrease in stomach cancer incidence were rated.
Discussion A comparison of several regional studies of the ethnic differences in cancer incidence in the United States demonstrates some consistent and interesting observations. According to reports submitted by the Advisory Committee to the Surgeon General of the Public Health Service, the primary risk factor for lung and bronchial cancer is cigarette smoking.5-7 Air pollution is also associated with increased lung cancer incidence, other causes are asbestos fibers and radon in mining and industry. As smoking, air, and industrial pollution problems have increased in the United States, the incidence of lung cancer has shown a general trend of escalation in recent years. The breast cancer incidence of all ethnic groups analyzed showed a steady trend of increase among white, black, Chinese, and Japanese females. For example, a rising incidence of breast cancer among Japanese women in California was documented. 1.2.8,9 Data for the native Japanese population were reported by Segi in 1970.8 The incidence of breast cancer increased from 14.4 percent of all cancers among native Japanese women to 36.2 percent of all cancers among CaliforRian-Japanese women under age 55.9 The rising incidence of breast cancer among all ethnic groups may be explained on the basis of cultural characteristics in the United States, eg, the delayed age of first delivery, high fat consumption, and socioeconomical fac-
tors.10O
The unusually high incidence of liver cancer and nasopharyngeal cancer among Chinese males has been investigated extensively.11-14 Genetic factors may be important, since both US Chinese and native Chinese in Taiwan showed similar cancer characteristics. The high incidence of stomach cancer among the Japanese population may be related to their cultural heritage as well as to genetic factors. A reduced stomach cancer incidence was observed among the US Japanese population in California, as compared to the exceedingly high stomach cancer death rate of the native Japanese population in Japan.1'2'9 Similarly, a reduction of stomach cancer incidence was also observed among the Spanish population, and the Chinese population in the western United States. Cultural changes, especially related to dietary habits, may contribute to the decline of stomach cancer incidence.
Literature Cited 1. The San Francisco Bay Area Resource for Cancer Epidemiolopy, vol 3, no. 1. Berkeley, Calif, State of California, Department of Public Health, 1973 2. Arellano MG, Linden G, Dunn JE: Cancer patterns in Alameda County, California. Br J Cancer 23:473-482, 1972 3. Buechley RW, Howard CA, Kutvirt DM, et al: Cancer Trends Among Ethnic Groups in New Mexico. Monterrey, Mexico, US-Mexico Border Public Health Association, 1974 4. Cancer statistics. Age-adjusted death rates per 100,000 population for selected cancer sites for 40 countries. World Health Statistics Annual, 1968-69. CA 25(1):8-21, 1975 5. Smoking and Health. In Advisory Committee to the Surgeon General of the Public Health Service (Washington DC): Report. PHS Publication No. 1103, 1964 , Supplemental Report, 1967 6. , Supplemental Report, 1972 7. 8. Segi M: Japan, Miyagi Prefecture. In Dali R, Muir CS, Waterhouse JAH: Cancer Incidence in Five Continents, vol 3. Geneva, UICC, 1970 9. San Francisco Bay Area Resource for Cancer Epidemiology: Japanese Cancer Project: Project Record. Berkeley, Calif, State of California, Department of Public Health, 1970 10. Zippin C, Petrokis NL: Identification of high risk groups in breast cancer. Cancer 28:1381-1387, 1971 11. Buell P: Nasopharynx cancer in Chinese of California. Br J Cancer 19:459-470, 1965 12. Clifford P: A review on the epidemiology of nasopharyngeal carcinoma. Int J Cancer 5:287-309, 1970 13. Muir CS: Nasopharyngeal carcinoma; A historical vignette. In Muir CS, Shanmagaratnam K: Cancer of the Nasopharynx. Geneva, UICC Monograph Series, 1967, p 47 14. Zippin C, Tekawa I, Bragg K, et al: Studies on heredity and environment in cancer of the nasopharynx. J Natl Cancer Inst 29:483490, 1962
JOURNAL OF THE NATIONAL MEDICAL ASSOCIATION, VOL. 71, NO. 4, 1979
