Patterns of Site-Specific Displacement in Cancer Mortality amongMigrants: The Chinese in the United States

HAITUNG KING, PHD, JUN-YAO LI, MD, FRANCES B. LOCKE, MS,EARL S. POLLACK, SCD, AND JI-TAO TU, MD

Abstract: Taking advantage of the information gathered for the1975 National Mortality-Survey in China, this paper compares thelevels of cancer mortality among foreign-born and United States-born Chinese around 1970 with those of the communities of origin ofthe majority of Chinese migrants to the US. Age-adjusted ratesindicate two distinctive site-specific patterns among US Chinese: adownward trend for cancers of high risk among Guangdong and

IntroductionIt has long been recognized that the migration of popula-

tions constitutes one of nature's unplanned experiments,providing an unusual opportunity to link different types andlevels of disease risk among migrants. Among the world'smajor migrant populations, the Chinese represent a uniqueresource for epidemiologic investigations on a variety ofdisease entities and, in particular, cancer. The Chinese havemigrated to many countries throughout the world, and themajority of residents in any populous Chinese community isknown to share a common geographic (county) backgroundand/or regional dialect with their ancestors on the homeland,such as the Chinese in the two major settlements included inthis study, Hong Kong and the United States.

Cancer mortality among Chinese in Hawaii and thecontinental United States was initially examined by Smith'for the years 1949-52, but no attention was given to nativitydifferences due to data limitations noted below. Systematicstudies by nativity began with two investigations by King,Haenszel, and Locke23 on the US Chinese, 1959-62 and1968-72. In the absence of comparable homeland data,cancer mortality experience among Chinese in Hong Kong,Singapore, and/or Taiwan province was used in these twostudies to ascertain risk levels. Taking advantage of thenational mortality statistics recently collected for the Peo-ple's Republic of China (PRC), 1973-75,4 this study seeksto identify specific patterns of cancer risk among Chinese offairly comparable ancestral origin in three areas, i.e., Guang-dong province, Hong Kong, and the United States. Aforthcoming study will deal with Chinese populations ofsimilar origin in three other geographic areas-migrants toTaiwan and Singapore from Fujian Province.Chinese in Hong Kong

Migration of the Chinese to Hong Kong dated back to asearly as the Han Dynasty (207 BC-220 AD), and theircontinuous settlement on the island began no later than the13th century.2 While the early settlers were mainly Fujien-

From the National Cancer Institute; Georgetown University; ChineseCancer Research Institute; and Shanghai Cancer Institute. Address reprintrequests to Haitung King, PhD, National Cancer Institute, Blair Building,Bethesda, MD 20205. This paper, submitted to the Journal July 16, 1984, wasrevised and accepted for publication October 1, 1984.Editor's Note: See also related editorial p 225 this issue.

© 1985 American Journal of Public Health 0090-0036/85 $1.50

Hong Kong Chinese (nasopharynx, esophagus, liver, uterus, andperhaps stomach) and an upward trend for those sites of low riskamong Chinese in Guangdong and Hong Kong (colon, lung, leuke-mia, and female breast). Further field studies are needed withemphasis on the birthplace of migrants and environmental changesin host countries. (Am J Public Health 1985; 75:237-242.)

ese, the majority of the population were, at the time ofBritish occupation in 1841, probably Cantonese,* Hakkas,Hoklos, and Tankas. The Tankas are a boat people orfishermen, descendants of an aboriginal tribe, who float offthe coast at various points but do not usually settle on theshore. The origins of Hong Kong residents in recent yearsmay be roughly identified by reference to dialect spoken:Cantonese, 79.0 per cent; Hakka, 4.9 per cent; Hoklo, 6.3per cent, Si Yi, 4.4 per cent; all others, 5.4 per cent. TheCantonese-speaking (90 per cent) Tankas constitute about 4per cent of the total population.Chinese in the United States

Up to the late 1800s, the majority of Chinese enteringthe United States came from two dialect-community clustersin Guangzhou province." The first group, San Yi, literallymeaning three districts (counties), includes Taishan, Kaip-ing, and Enping; the second group, Si Yi (four districts orcounties), is composed of Xihui, Shunde, Nanhai, andFanyu. Since the early 20th century, Chinese immigrantsfrom Zhongshan county in the same province have emergedas a new major segment of US Chinese. With the exceptionof Fanyu, all seven other districts are parts of the Foshanprefecture which also has jurisdiction over five additionalcounties.

More recently, with the repeal of the National OriginsQuota Act in 1965, the number of Chinese admitted to theUS has increased dramatically.6 As a result, the birth originof US Chinese has become somewhat more diversified,although the usual predominance of Guangdong descendantsseems to hold. For example, a large number of Cantonese-speaking Chinese among the new influx of immigrants wererelated to-members of the eight major population segmentsnoted above.7 The majority of Chinese Americans are con-centrated in San Francisco, New York City, Honolulu, andLos Angeles.

Aside from the great increase in the size of the USChinese population since the 1960s (1970:435,062;1980:805,027), the significance of the Chinese as a resourcefor cancer research has been further enhanced by a parallelproportional change in the distribution of foreign-born (idai)

*They were so identified by the dialect they spoke, that of the majority ofresidents of Guangdong province; the dialect was named after the capital cityof that province, Canton, now spelled as "Guangzhou," which is about 90miles from Hong Kong.

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KING, ET AL.

and native-born (erdai) Chinese.**2., 68.9 Prior to 1960, theproportion of erdai over age 45 (ages most significant forcancer) was too small for meaningful analysis; since 1960,the number of erdai has increased considerably so that, by1970, 18 per cent of males and 15 per cent of females hadattained this age. This change made possible the two pio-neering nativity studies at the national level noted earlier.2.3

This cursory review of the origins of study subjectsindicates that the majority of Chinese in Hong Kong and theUnited States came from the Guangdong area. Presumably,some of the cancer risks to be noted later may reflect certaingenetic and/or cultural traits that characterize the two mi-grant groups of our study.

MethodsTable 1 presents total numbers and per cent distribution

by age for each sex or sex-nativity group for the three studypopulations, along with the sources of information. The agedistributions for Guangdong, Hong Kong, and erdai werequite similar: 50 per cent under age 20 and 20 per cent at age45 and over. In contrast, for idai, only 20 per cent are underage 20 and well over 30 per cent are age 45 and over. ForGuangdong and Hong Kong, females were somewhat olderthan males, but for erdai and idai, males were slightly olderthan females. One other noted characteristic relates toresidence. The Chinese populations in the United States and

**The two terms are equivalent to issei and nisei, conventionally used inepidemiologic and popular literature and standard references including Web-ster, to denote foreign-born and native-born Japanese (i in Chinese means firstand er, second; in Japanese ichi and ni; dai, meaning generation, is compara-ble to the Japanese set).

Hong Kong were highly urbanized, compared to their coun-terparts in Guangdong who are predominantly rural.

Cancer mortality data for US Chinese in the threelocalities, 1968-72, were provided by the respective healthdepartments. The total number of male and female deathsshown in Table 2 represent 75.9 and 79.0 per cent, respec-tively, of all cancer deaths among Chinese in the UnitedStates during the five years. Cancer mortality statistics forGuangdong refer to the PRC survey data of 1973-75 notedearlier. Information on cancer deaths for Hong Kong, 1969-73, was derived mainly from the publications of the WorldHealth Organization,'0 supplemented by data supplied bythe Hong Kong Medical and Health Department.

Classification of deaths from malignant neoplasmsamong US and Hong Kong Chinese was in accordance withthe 8th revision of the International Classification of Dis-eases and Causes of Death (ICD). Certain cancer sitesshown for Guangdong were not strictly comparable withthose for Hong Kong and the United States, because theGuangdong deaths were coded according to an old classifica-tion scheme prepared by the Ministry of Health. "I To adjustfor some of the known PRC area variations in the classifica-tion of specific cancer sites, data were combined for cervixand other uterus, and for colon and rectum.

The small numbers of deaths in most age groups pre-clude undue emphasis on age-specific rates by site. For ratescomputed for Guangdong, there are slight variations forseveral sites between those presented in this paper and thecorresponding figures appearing in a Chinese source.'4

Methods of age adjustment and computation of confi-dence limits (for idai and erdai) are described in Table 2footnotes.

TABLE 1-Per Cent Distribution by Age for Each Sex of Chinese Populations in Guangdong Province,People's Republic of China, 1975; Hong Kong, 1971; and United States by Nativity, 1970.

U.S.***Hong

Age Guangdong* Age Kong** Idai Erdai

MalesTotal Number 24,900,000 2,000,000 66,931 85,834

(Percent) (Percent)<10 26.7 <15 36.3 12.0 37.9

10-19 23.0 15-24 19.9 17.2 21.720-29 15.4 25-34 11.3 16.3 9.830-39 12.1 35-44 12.8 17.9 10.940-49 10.0 45-54 10.5 14.6 9.550-59 6.7 55-64 6.3 11.1 5.760-69 4.1 65-74 2.3 7.7 3.370-79 1.7 -75 0.6 3.2 1.2.80 0.4

Total 100.0 100.0 100.0 100.0Females

Total Number 24,700,000 1,900,000 64,270 77,371(Percent) (Percent)

<10 25.6 <15 35.7 11.5 39.510-19 21.5 15-24 19.2 19.3 22.820-29 14.5 25-34 9.7 18.6 9.930-39 11.5 35-44 12.0 18.8 10.940-49 10.1 45-54 10.2 12.1 8.950-59 7.4 55-64 7.2 10.3 4.560-69 5.6 65-74 4.2 6.7 2.570-79 2.8 -75 1.9 2.7 1.0.80 0.9

Total 100.0 100.0 100.0 100.0

*Based on a 10 per cent sample population census for 1975 conducted in connection with the 1973-75 National Mortality Survey.5**Based on 1971 census population.11"-Based on 1970 Chinese population in California, Hawaii, and New York City which constitutes 70 per cent of total US Chinese.3

AJPH March 1985, Vol. 75, No. 3238

CANCER MORTALITY IN CHINESE MIGRANTS TO US

ResultsOverall Cancer Mortality

For all cancers combined, mortality for idai and HongKong males was substantially higher than for their erdai andGuangdong counterparts (Table 2, Figure 1). Similarly, therisk for Guangdong females was half that for Hong Kong andUS Chinese women, but the rate for erdai females wasalmost as high as that for idai women. Examination of age-specific mortality further revealed that, among Hong Kongand US Chinese of both sexes, there were consistentlyhigher mortality rates for successive age groups (Figure 2).Among Guangdong males and females, however, such anincreasing risk continued only up to around age 50, afterwhich there was a leveling off, accompanied by a noticeabledecline after age 80 among males. One is thus tempted toinfer that the lower cancer risk observed for Guangdongmight be a reflection of the much lower mortality in its agedpersons, provided that both population and mortality figuresentering into rate computation are valid.

It should be emphasized, however, that no undue signif-icance should be placed on area differences in total cancermortality because areas vary greatly in their distribution byindividual primary sites. For example, although Guangdongdisplayed an overall low cancer risk, a high rate was shownfor those sites to which the Chinese are known to beespecially vulnerable. Thus, not only was the rate for cancerof the esophagus in Guangdong much higher than that for allother study populations, the risks for cancers of the naso-pharynx, liver, and uterus also exceeded those for USChinese. Hong Kong had even higher mortality rates foreach of these latter three sites. For cancers of the colon,

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FIGURE 1-Age-Adjusted Death Rates of Malignant Neoplasms among Chineseby Site, Sex, and Area, Guangdong, 1973-75; Hong Kong, 1%9-73; UnitedStates by Nativity, 1968-72.

breast, and leukemia, however, US Chinese displayed thehighest rates.Patterns of Displacement

Of particular interest was the observation of distinctpatterns in rate differentials between Asian and US Chinese.For those cancers associated with high risk in Guangdong

TABLE 2-Total Number of Deaths and Age-adjusted Mortality Rats* for Malignant Neoplasms, by Site and Sex, for Chinese Populations In GuangdongProvince, People's Republic of China, 1973-75; Hong Kong 1969-73; and Unitd Sttes by Nativity, 1966-72

Number of Deaths Rate/100,000 95% Confidence Limits

Site Guangdong Hong Kong Idai Erdai Guangdong Hong Kong Idai Erdai ldai Erdai

Males

All cancers 45956 12146 977 282 85.9 174.7 201.0 90.4 188.3-213.7 79.7-101.1Nasopharynx 7082 1383 52 12 12.7 16.0 11.3 3.6 8.2-14.4 1.5-5.7Esophagus 8284 761 39 11 16.7 11.5 7.2 3.8 4.9-9.5 1.5-6.1Stomach 5767 1161 72 17 11.4 18.1 14.6 6.0 11.2-18.0 3.1-8.9Colon 2259 469 86 32 4.4 7.8 17.1 11.0 13.5-20.7 7.2-14.8Rectum 2 320 37 10 5.1 7.5 3.6 5.1-9.9 1.4-5.8Liver 12494 2694 86 11 22.7 36.4 17.8 3.7 14.0-21.6 1.6-5.8Lung 4052 2685 276 60 8.0 41.5 55.7 19.5 49.1-62.3 14.5-24.5Leukemia 1973 289 23 16 2.7 3.0 5.4 4.2 2.9-7.9 2.1-6.3Other 4045 2384 306 113 7.3 35.3 64.4 35.0 - -

Females

All cancers 30915 8808 370 192 48.4 99.0 88.1 81.3 79.1-97.1 69.4-93.2Nasopharynx 3246 550 13 7 5.1 6.2 3.1 2.3 1.4-4.8 0.5-4.1Esophagus 5770 307 2 0 9.2 3.5 0.5 0.0 0.1-1.1Stomach 3252 796 27 12 5.2 9.0 6.2 5.7 3.8-8.6 2.4-9.0Colon 1913 495 25 23 3 5.6 5.9 10.8 3.6-8.2 6.3-15.3Rectum 1 250 10 5 . 2.8 2.3 2.1 0.8-3.8 0.2-4.0Liver 4267 768 12 3 6.7 8.7 2.9 1.4 1.3-4.5 0.0-3.0Lung 2117 1774 54 31 3.4 20.2 12.7 14.4 9.3-16.1 9.2-19.6Breast 2188 827 49 29 3.5 9.3 11.8 11.8 8.5-15.1 7.4-16.2Uterus 4002 925 26 10 6.4 10.3 6.1 4.4 3.7-8.5 1.6-7.2Leukemia 1470 256 18 14 2.0 2.6 4.2 3.9 2.2-6.2 1.7-6.1Other 2690 1860 134 58 4.1 22.7 34.9 27.1 - -

*Age adjusted to the world population standard,12 by direct method.-Computed in accordance with the WHO Manual of Mortality Analysis.13

AJPH March 1985, Vol. 75, No. 3

I

239

-11-M. AI R.A.1 M.A.Irvm

KING, ET AL.

MALES

10000

1000

100

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GUANGDONGHO- GHKONG

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1001

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FIGURE 2-Age-Specific Death Rates of All Malignant Neoplasms amongChinese by Sex and Area, Guangdong, 1973-75; Hong Kong, 1969-73; UnitedStates by Nativity, 1968-72.

and Hong Kong Chinese (i.e., nasopharynx, esophagus,liver, and uterus, and perhaps stomach), lower rates wereexhibited in US Chinese, particularly among erdai. In con-trast, for cancers with low risk in Asian Chinese (i.e., colon,lung, leukemia, and female breast), rates were higher for theUS Chinese.

Overall and by specific cancer site, there was a higheridai than erdai mortality, regardless of the above patterns ofvariation, with the exceptions of cancers of the colon, lung,and breast among females. Among males, the confidencelimits of mortality rates for the two nativity groups over-lapped somewhat for certain cancer sites. Among idai anderdai females, however, there was overlap in confidencelimits for each site observed. More significantly, regardlessof direction of change, the 95 per cent confidence limitsshowed that erdai rates were significantly different fromthose in Guangdong for each site, except leukemia, uterus,and stomach (females).Downward Transition

Nasopharynx-Table 2 shows that Hong Kong malesdisplayed the highest mortality from nasopharyngeal cancer,whereas the relatively high rates for Guangdong and idaimales surpassed that for erdai. The ordering of risk may berelated to the proportion of residents with high risk in theparental population (Guangdong) and the composition ofsuch segments among settlers in a host area (Hong Kong,US). Thus, for Guangdong, although a high risk was shownfor the urban sector of Guangzhou municipality and Foshanprefecture (Table 3), the combined numbers of residents inboth areas constituted only about 20 per cent of the popula-tion of the entire province. That the risk for Guangdong wasbelow that for Hong Kong may be attributable to the lowermortality shown for most other communities in that prov-ince, some of which had rates under 2 per 100,000.'4 ForHong Kong, with the majority of its population composed ofCantonese, its high mortality for this cancer site was furthersharpened by the inclusion of another high-risk group-theboat people (Tankas)."s Furthermore, while a large segmentof US Chinese originated in the high-risk Foshan prefectureand Zhongshan county, there was a noticeable admixture ofmigrants from other parts of China where below averagerates prevailed. This might account, in part, for the lowernasopharyngeal cancer mortality rates among US Chinesewhen compared to their Asian counterparts.

TABLE 3-Age-adjusted Mortality Rates* for Malignant Neoplasms, bySite and Sex, Selected Areas in Guangdong Province, Peo-ple's Republic of China, 1973-75

Foshan Prefecture GuangzhouMunicipality Remainder

Site Total Zhongshan County Urban Area of Province

Males

All cancers 90.4 94.5 105.1 84.2Nasopharynx 18.5 20.2 16.8 11.6Esophagus 4.9 3.7 9.0 19.1Stomach 8.9 10.5 10.3 11.9Colon-rectum 5.3 5.7 6.4 4.1Liver 31.4 31.0 24.2 21.4Lung 9.4 7.3 22.7 6.7Leukemia 3.6 3.8 2.7 2.5Other 8.1 12.2 12.8 6.9

Females

All cancers 50.7 60.6 57.4 47.0Nasopharynx 7.7 10.2 7.3 4.6Esophagus 1.8 1.8 3.5 10.8Stomach 5.4 5.0 5.2 5.1Colon-rectum 3.7 5.9 3.8 2.8Liver 8.1 6.4 7.0 6.4Lung 3.7 3.7 8.7 2.7Breast 4.9 7.9 4.7 3.1Uterus 7.8 9.0 9.0 5.9Leukemia 2.7 3.0 2.4 1.9Other 4.8 7.7 5.9 3.8

*Age adjusted to the world population standard,12 by direct method.

The notably lower mortality observed for erdai than foridai was consistent with the 1959-62 profile reported earli-er,2 especially among males. The complications arising fromthe recent influx of Hong Kong Chinese below cancer agecannot be adequately ascertained for years to come.

Esophagus-Risk levels were shown successively lowerfrom Guangdong to Hong Kong, and from idai to erdai, aphenomenon not to be found for any other cancer siteexamined in this paper. Further, the conspicuous disparatemale-female experience noted for US Chinese and theirAsian counterparts was in keeping with the usual patterndescribed for migrants from some European countries inwhich the male esophageal cancer risk far exceeded that forfemales. However, the lower risk of this cancer among USChinese than among the mainland Chinese population ap-pears to run counter to the experience of several migrantgroups to the United States from Europe and Japan.'6'7Incidentally, most of the counties in the Foshan prefectureshowed a much lower esophageal cancer mortality than theremainder of Guangdong province 14 which might partlyexplain the low mortality risk for idai. Furthermore, the lowmortality from this cancer among US Chinese was consistentwith the risk level observed in this population for 1959-62.3

Stomach-Cancer of the stomach was reported in the1975 PRC National Mortality Survey to be the leading causeof cancer deaths.5 As one of the few low-risk areas of thisdisease in China, Guangdong had about one-third the mortal-ity level of that for the entire country. Taking the Guangdongexperience as the homeland reference level, no clear-cutdifference in stomach cancer mortality is seen betweenGuangdong and US Chinese except perhaps for erdai males.This calls for reassessment of the downward transitionalpattern of this cancer site usually held for US Chinese, basedon risk levels of Taiwan province, Hong Kong, and Singa-

AJPH March 1985, Vol. 75, No. 3240

CANCER MORTALITY IN CHINESE MIGRANTS TO US

pore.23 The pattern observed here is consistent with theexperience of several European and Japanese migrantgroups to the US in that stomach cancer risk was linkedmore closely to the place of origin than to the host popula-tion. 16,17 For Hong Kong, however, the higher risk over thatfor Guangdong did not follow this pattern.

Liver-for many years the Chinese have been known tobe at high risk for primary cancer of the liver. The high levelof mortality described for Guangdong supports the findingson the Chinese in Taiwan province, Singapore, and BritishColumbia.2'3 The much higher risk shown for Hong Kongthan for Guangdong is particularly striking, in view of thefact that mortality from liver cancer for Guangdong approxi-mated the national level.5 The Hong Kong rate also exceed-ed slightly that for Guangxi, a neighboring province toGuangdong, which was reported to be at the highest risk forliver cancer among the 29 administrative areas included inthe national survey.

The mortality rate noted for idai was lower than that ofGuangdong even though the majority of them came from thehigh-risk areas of Foshan prefecture and Zhongshan countyin that province where the mortality levels (males) were overone-third higher than that of Guangdong (Table 3). Thenumber of male and female deaths in both US nativitygroups was too small to warrant separate comment. Howev-er, considering the high sex-ratio noted in this and otherstudies2.3 for Guangdong, Hong Kong, Singapore, and Tai-wan province, a noticeable male-female risk differential forliver cancer in the Chinese populations seems to be indicat-ed.

Uterus-In recognition of the known dissimilar epide-miologic features of cancers of the cervix and "other uter-us," caution must be taken in the interpretation of thecombined rates for Asian and American Chinese. One majordifficulty relates to the certifying practices of some Asiancommunities where the high risk for "other uterus" is likelyto have been grossly inflated through inclusion of cervixdeaths.2 The relatively small number of deaths from eithersite entering into rate computation for idai and erdai furthercomplicates problems of comparison. International studiesof migrant populations have indicated that risk levels forcancers of the breast, corpus uteri, and ovary tend to vary ina similar manner.'6 '7 Since Chinese in Hong Kong, Taiwan,and Singapore have higher cervical cancer rates than USChinese, but lower breast and ovarian risk, the need forseparate consideration of cervix and "other uterus" is clear.Such an analysis is not possible with the limited data at ourdisposal.

Upward TransitionColon and Rectum-Separate data on colon cancer are

not available for Guangdong. Judging from the combinedcolon-rectum rates for Guangdong and independent HongKong figures (assuming colon rates predominate), the mor-tality from colon cancer for idai (males) and erdai is consid-erably higher than for Guangdong and Hong Kong. Ofinterest is the higher risk observed for erdai than for idaifemales, representing a transposition of the 1959-62 profile.As King and Haenszel suspected earlier,2 the transitionalexperience of the Chinese may eventually conform to theinternational pattern linking colon cancer mortality moreclosely to the host than to the home country.'6-'8

Lung-Compared to their counterparts in Guangdong, apredominantly rural province, mortality from cancer of thelung was much higher in all other Chinese populations,

particularly for idai and Hong Kong males of all ages. Theurban area of Guangzhou municipality also displayed aconsiderably high risk for this cancer, especially amongmales, being over twice as high as that for Guangdongprovince as a whole (Tables 2, 3). This urban-rural disparitywas also reported for the "town" and "outskirt" areas forZhongshan county in the same province.'9 All this seems topoint to the importance of urban experience in assessing therisk level of lung cancer among the various Chinese popula-tions. It is further noted that since 1960 there was a notice-able increase in lung cancer mortality among idai whichseemed to be partly a reflection of the recent influx of HongKong Chinese. In fact, a rapid increase in mortality for thiscancer has been reported for the Chinese in Hong Kongsince 1961.20

Among US Chinese females, both idai and erdai, themortality rates since 1960 exceeded that for US Whitewomen (the corresponding rate for 1970 being 9.2). In viewof the general impression that a substantial number of AsianChinese may have been underdiagnosed for lung cancer,2 theactual risk differential between Hong Kong and US Chinesefemales may be greater than indicated.

Female Breast-The generally known low breast cancerrisk for Oriental females was once again reinforced by thelow mortality shown for Guangdong at all ages. The similarlylow risk observed for all other areas in that provincesupports such an impression. '4 Although a higher mortalitywas observed for Hong Kong and for idai and erdai, the risklevels were still below the rate of 2.7 for US White females.Thus it seems evident that breast cancer risk for US Chinesefemales remained more closely linked to that of their Asiancounterparts, as was the case with Japanese migrants to theUS.16

Leukemia-The extremely low mortality from leukemiadescribed for Guangdong was consistent with what has beenpreviously reported for the Chinese in various areas.2 Asindicated in Table 2, no significant variations were shown forthe leukemia risk among the study populations. For Chinesein Guangdong, there were no major risk differentials by age,and only a slight increase in risk was observed for HongKong Chinese aged 40 and over. Despite the small number ofleukemia deaths among US Chinese, there were indicationsthat among adults and perhaps children, mortality fromleukemia may be higher for US Chinese than for AsianChinese. Further investigations, when more cases are accu-mulated, are needed to explain these differences. Onceagain, the Asian-US Chinese contrast may be complicatedby suspected underdiagnosis prevailing among Asian Chi-nese.

Direction of Transition IndeterminateOther Sites-Several other cancer sites are not included

in our discussion because data on them were not availablefrom Guangdong. However, these non-specified sites (Table2) comprised only 8 per cent of the total cancer rate in thatprovince, compared to 20 per cent in Hong Kong, and 30-40per cent among idai and erdai. These sites include, primarily,pancreas, prostate, ovary, gallbladder, kidney, brain, andlymphomas.

DiscussionFor all cancers combined, a higher risk was observed

among urban Chinese in Hong Kong and US idai males,whereas Chinese in rural Guangdong generally exhibited alower mortality. A similar pattern was described for cancer

AJPH March 1985, Vol. 75, No. 3 241

KING, ET AL.

of the lung. In terms of international migration experience,the higher mortality for colon/rectum cancer shown amongUS Chinese, along with the apparent rise in female breastcancer, compared to the homeland population, were allconsistent with the transitional patterns reported for Japa-nese and European migrants to the United States. However,the fact that the esophageal cancer risk among idai males islower than that in Guangdong and Hong Kong, appears torun counter to the experience of other migrant groups to thiscountry.

For cancer of the nasopharynx, the much higher mortal-ity exhibited in US Chinese compared to US Whites seemsconsistent with the high risk shown for Guangdong andparticularly Hong Kong. As indicated earlier, all thesepopulations share a common ancestral background. Of par-ticular interest was the much lower stomach cancer mortal-ity reported for Guangdong, in contrast to the noticeablyhigh risk shown for Hong Kong, Singapore, and Taiwanprovince, on the basis of which mortality transition amongUS Chinese has been ascertained until now. Taking Guang-dong as the norm, no clear downward displacement in thiscancer seemed to be indicated among US Chinese. Furtherfield studies are needed of this and other cancer sites invarious Chinese populations, with emphasis on the birth-place of residents and environmental changes.

The use of 1975 PRC mortality survey data in our initialanalysis has been fruitful, particularly in the identification oftwo distinctive patterns of displacement prevailing over USChinese, i.e., a downward transition for cancers with highrisk among Asian Chinese (nasopharynx, esophagus, liver,and uterus, and perhaps stomach) and an upward displace-ment for those sites of low risk shown for Guangdong andHong Kong (colon, lung, leukemia, and female breast).

REFERENCES1. Smith L: Recorded and expected mortality among the Chinese in Hawaii

and the United States, with special reference to cancer. JNCI 1956;17:667-676.

2. King H, Haenszel W: Cancer mortality among foreign- and native-bornChinese in the United States. J Chron Dis 1973; 26:623-646.

3. King H, Locke FB: Cancer mortality among Chinese in the United States.JNCI 1980; 63:1141-1148.

4. Editorial Committee for the Atlas of Cancer Mortality in the People'sRepublic of China: Atlas of Cancer Mortality in the People's Republic ofChina. Shanghai: China Map Press, 1979.

5. Office of Cancer Prevention and Treatment, Depar-tment of Health:Analytic Findings of the Cancer Mortality Survey in China. Beijing,People's Publisher, 1976 (in Chinese).

6. King H. Locke FB: Chinese in the United States: A century of occupa-tional transition. Int Migr Rev 1980; 14:15-42.

7. Annual Report 1980. Chinese Newcomers Service Center. San Francisco.(n.d.).

8. King H: Selected epidemiologic aspects of major diseases and causes ofdeath among Chinese in the United States. in: Kleinman H, et al (eds):Medicine in Chinese Cultures: Comparative Studies of Health Care inChinese and Other Societies. DHEW Pub. No. (NIH) 75-653. Washing-ton, DC: Govt Printing Office, 1975.

9. King H: Mortality among foreign- and native-born Chinese in the UnitedStates. In: Murata AK, Farquhar J (eds): Issues in Pacific/Asian Ameri-can Health and Mental Health. Chicago: Pacific/Asian American MentalHealth Research Center, 1982.

10. World Health Organization: World Health Statistics Annual. Geneva:WHO, 1969-1973.

11. King H, Locke FB: Selected indicators of current health status and majorcauses of death in the People's Republic of China: an historical perspec-tive. In: Scherer JL (ed): China Facts and Figures Annual. Gulf Breeze,FL: Academic International Press, 1983.

12. Waterhouse J, Correa P, Muir C, Powell J: Cancer Incidence in FiveContinents, Vol III. Lyon: IARC Scientific Publishing, 1976.

13. World Health Organization: Manual of Mortality Analysis. Geneva:WHO, 1976.

14. Office of Cancer Prevention and Treatment, Department of Health:unpublished data from the 1973-75 Mortality Survey in the People'sRepublic of China.

15. Ho HC: Nasopharyngeal carcinoma in Hong Kong. In: Muir CS, Shanmu-garatnam K (eds): Cancer of the Nasopharynx. New York: Med Exam,1967.

16. Haenszel W. Kurihara M: Studies of Japanese migrants. 1. Mortality fromcancer and other diseases among Japanese in the United States. JNCI1968; 40:43-68.

17. Locke FB, King H: Cancer mortality risk among Japanese in the UnitedStates. JNCI 1980; 63:1149-1156.

18. Haenszel W: Cancer mortality among the foreign-born in the UnitedStates. JNCI 1961; 26:37-132.

19. Zong Y: Primary lung cancer mortality rate in Zhongshan county. ChineseMed J 1981: 94:141-142.

20. Ho HC, et al: Cancer in Hong Kong: some epidemiological observations.In: Third Symposium on Epidemiology and Cancer-Registries in thePacific Basin, NCI Monograph No. 62, NIH Pub. No. 82-2438. Washing-ton, DC: Govt Printing Office. 1982.

ACKNOWLEDGMENTThe inclusion in our analysis of unpublished data on Guangdong province

was made possible through the courtesy of Dr. Li Ping, former director of theChinese Cancer Institute. Beijing, to whom we wish to express our mostsincere thanks. We also wish to extend the same to Dr. Max Myers. NationalCancer Institute, for his helpful suggestions in the preparation of this paper.

Awards: Graduate Education in Public Health Nutrition 1The American Public Health Association, Food and Nutrition Section, announces and invites

nominations for the 1985 Helen R. Stacey and Joseph A. Walsh Awards for graduate education inpublic health nutrition. Three awards for $2000 each will be given.

The American Public Health Association, Food and Nutrition Section also solicits nominations forthe 1985 Mary C. Egan Award which recognizes a young public health nutritionist.

For further information on all of the above, contact: Barbara Duvekot, Prince George's CountyHealth Dept., D. Leonard Dyer Memorial Health Center, 9314 Piscataway Road, Suite 201, Clinton,MD. 20735. Deadline May 1, 1985.

242 AJPH March 1985, Vol. 75, No. 3