Cancer among Hispanic children in California, 1988-1994: comparison with non-Hispanic white children.

BACKGROUND: There has been a perception that California Hispanic children have an unusually high cancer incidence rate, but to the authors' knowledge the only information regarding cancer rates in this population has been the tabular data published in reports issued by the California Department of Health Services. The California Cancer Registry has collected data regarding all cancers diagnosed in California since 1988. METHODS: Data regarding all invasive cancers diagnosed in California Hispanic children age <15 years during the 7-year period 1988-1994 were analyzed. Cancers were grouped according to the International Classification for Childhood Cancers. Age-adjusted and age specific incidence rates were compared with the corresponding incidence rates among non-Hispanic white children. RESULTS: Based on available demographic information, the overall incidence rate of cancer was approximately 7% lower among California children classified as Hispanic than among non-Hispanic white children. Hispanic children had higher incidence rates of lymphoid leukemia and gonadal germ cell tumors and a lower incidence rate of astrocytomas and carcinomas than non-Hispanic white children. CONCLUSIONS: These data do not confirm the perception that California Hispanic children have an unusually high cancer incidence rate but there were notable differences between Hispanic and non-Hispanic white children with regard to the incidence rates of certain cancers. The perception may be due in part to the fact that childhood malignancies represented 3.1% of all cancers diagnosed among Hispanics but only 0.5% of all cancers diagnosed among non-Hispanic whites. This is explained by the lower incidence rate of cancer among California Hispanic adults than among non-Hispanic white adults and the difference in the age distribution of the two populations.     

International patterns of cancer incidence in adolescents

International patterns of childhood cancer incidence are well documented but equivalent information relating to adolescence is scarce. This article synthesizes international data on cancer in adolescents from population based cancer registries. Total incidence ranged from 95 to 255 per million person years in the series studied. The highest rates were in Australia and among Jews in Israel and the lowest in India and Japan. Lymphomas were the most frequent cancers in western industrialised countries of the northern hemisphere and in the Middle East, and occurred in substantial numbers in all other regions. Hodgkin lymphoma outnumbered non-Hodgkin in western industrialised countries but was relatively rare in most developing countries and in Japan. Leukaemias were the most frequent diagnostic group in India, East Asia and Latin America. Melanoma was the commonest cancer of adolescents in Australia and New Zealand and moderately frequent in many other predominantly white populations but rarely seen elsewhere. Kaposi sarcoma was the most frequent cancer in both sub-Saharan African series studied. The highest rates for nasopharyngeal carcinoma were in Algeria and Hong Kong and for liver carcinoma in Hong Kong and sub-Saharan Africa. Testicular germ cell tumours were relatively frequent in predominantly white populations. Central nervous system tumours and thyroid carcinoma were most often registered in countries with higher standard of living. Osteosarcoma was moderately frequent almost everywhere. Characteristic embryonal tumours of childhood and the most common carcinomas of adulthood were rarely seen. Only osteosarcoma, ovarian germ cell tumours and, in some populations, nasopharyngeal carcinoma have their highest incidence at age 15-19 years. Total cancer incidence was higher in adolescent males than females, but there was often a female excess in melanoma and thyroid carcinoma, and Hodgkin lymphoma was at least as frequent among females as males in several countries with relatively high incidence. More complete delineation of worldwide patterns of cancer in adolescence would be facilitated by availability of more data classified in a standard way to take account of morphology.     

Epidemiologic evidence for the role of indoor tobacco smoke as an initiator of human breast carcinogenesis.

Earlier research suggested an appreciable latent period between the time of exposure to indoor tobacco smoke and the detection of breast cancer. A close relationship was found in the U.S. between state breast cancer mortality from 1978 through 1981 and state cigarette sales from 1950 through 1954 (R = 0.64, p less than 0.001). The correlation declined for sales in subsequent years but remained highly significant until 1970, but not thereafter. Thus, it appears that the role of indoor tobacco smoke in breast carcinogenesis is that of an initiator and/or an early-stage promoter in the process that leads after 15 to 30+ years to cancer. Trends in cigarette consumption from 1915 to 1965 paralleled breast cancer incidence in Connecticut women from 1935 to 1989. The 1953 and 1975 peaks in incidence were related to 1930 and 1953 peaks in cigarette consumption, respectively, showing a 22.5-year latent period. The drop in cigarette sales in the mid-1950s was followed by a surge to new highs in sales in the early 1960s in the great majority of the states. Approximately 23 years later, breast cancer incidence rates in the mid-1980s in all nine SEER populations are reflecting that surge in cigarette sales, rising to an all-time high in 1985. The earliest declines in breast cancer incidence should occur in New York and Connecticut, where cigarette sales have fallen most dramatically. By the year 2015, white women in the South, currently living with the men with the highest lung cancer rates in the U.S., are expected to show the highest breast cancer rates in the country.     

Cancers of the prostate and breast among Japanese and white immigrants in Los Angeles County

Using age-adjusted incidence rates and proportional incidence ratios, the risks of prostate cancer and breast cancer in three racial/ethnic groups - Spanish-surnamed whites, other whites and Japanese - were studied in Los Angeles County native residents and compared with those in immigrants and representative 'homeland' populations. An algorithm based on social security numbers was developed and utilised to estimate age at immigration for non-US-born Los Angeles County cancer patients. For prostate cancer, the incidence rates in Los Angeles County were much higher than those in the homelands for each racial/ethnic group. However, prostate cancer rates of immigrants were similar to those of US-born patients in the Spanish-surnamed white and Japanese populations, regardless of age at immigration. For breast cancer, the incidence rates in Los Angeles County were also high compared with those in the homelands. However, the timing of immigration to the US was important in determining breast cancer risk. When social security numbers indicated that migration occurred later in life, rates for breast cancer were substantially lower than when migration occurred early, although they were still much higher than in the homeland populations. These findings suggest that environmental factors in early life rather than in later life are important in the etiology of breast cancer and that later life events can substantially impact the likelihood of developing clinically detectable prostate cancer.     

Incidence of primary liver cancer in American Indians and Alaska Natives,US, 1999–2009

Purpose

To evaluate liver cancer incidence rates and risk factor correlations in non-Hispanic AI/AN populations for the years 1999–2009.

Methods

We linked data from 51 central cancer registries with the Indian Health Service patient registration databases to improve identification of the AI/AN population. Analyses were restricted to non-Hispanic persons living in Contract Health Service Delivery Area counties. We compared age-adjusted liver cancer incidence rates (per 100,000) for AI/AN to white populations using rate ratios. Annual percent changes (APCs) and trends were estimated using joinpoint regression analyses. We evaluated correlations between regional liver cancer incidence rates and risk factors using Pearson correlation coefficients.

Results

AI/AN persons had higher liver cancer incidence rates than whites overall (11.5 versus 4.8, RR?=?2.4, 95% CI 2.3–2.6). Rate ratios ranged from 1.6 (Southwest) to 3.4 (Northern Plains and Alaska). We observed an increasing trend among AI/AN persons (APC 1999–2009?=?5%). Rates of distant disease were higher in the AI/AN versus white population for all regions except Alaska. Alcohol use (r?=?0.84) and obesity (r?=?0.79) were correlated with liver cancer incidence by region.

Conclusions

Findings highlight disparities in liver cancer incidence between AI/AN and white populations and emphasize opportunities to decrease liver cancer risk factor prevalence.

     

Annual report to the nation on the status of cancer, 1975-2001, with a special feature regarding survival

BACKGROUND: The American Cancer Society (ACS), the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updated information regarding cancer occurrence and trends in the U.S. This year's report features a special section on cancer survival. METHODS: Information concerning cancer cases was obtained from the NCI, CDC, and NAACCR and information concerning recorded cancer deaths was obtained from the CDC. The authors evaluated trends in age-adjusted cancer incidence and death rates by regression models and described and compared survival rates over time and across racial/ethnic populations. RESULTS: Incidence rates for all cancers combined decreased from 1991 through 2001, but stabilized from 1995 through 2001 when adjusted for delay in reporting. The incidence rates for female lung cancer decreased (although not statistically significant for delay adjusted) and mortality leveled off for the first time after increasing for many decades. Colorectal cancer incidence rates also decreased. Death rates decreased for all cancers combined (1.1% per year since 1993) and for many of the top 15 cancers occurring in men and women. The 5-year relative survival rates improved for all cancers combined and for most, but not all, cancers over 2 diagnostic periods (1975-1979 and 1995-2000). However, cancer-specific survival rates were lower and the risk of dying from cancer, once diagnosed, was higher in most minority populations compared with the white population. The relative risk of death from all cancers combined in each racial and ethnic population compared with non-Hispanic white men and women ranged from 1.16 in Hispanic white men to 1.69 in American Indian/Alaska Native men, with the exception of Asian/Pacific Islander women, whose risk of 1.01 was similar to that of non-Hispanic white women. CONCLUSIONS: The continued measurable declines for overall cancer death rates and for many of the top 15 cancers, along with improved survival rates, reflect progress in the prevention, early detection, and treatment of cancer. However, racial and ethnic disparities in survival and the risk of death from cancer, and geographic variation in stage distributions suggest that not all segments of the U.S. population have benefited equally from such advances.     

Annual report to the nation on the status of cancer, 1975-2003, featuring cancer among U.S. Hispanic/Latino populations

BACKGROUND: The American Cancer Society, Centers for Disease Control and Prevention, National Cancer Institute, and North American Association of Central Cancer Registries collaborate annually to provide U.S. cancer information, this year featuring the first comprehensive compilation of cancer information for U.S. Latinos. METHODS: Cancer incidence was obtained from 90% of the Hispanic/Latino and 82% of the U.S. populations. Cancer deaths were obtained for the entire U.S. population. Cancer screening, risk factor, incidence, and mortality data were compiled for Latino and non-Latino adults and children (incidence only). Long-term (1975-2003) and fixed-interval (1995-2003) trends and comparative analyses by disease stage, urbanicity, and area poverty were evaluated. RESULTS: The long-term trend in overall cancer death rates, declining since the early 1990s, continued through 2003 for all races and both sexes combined. However, female lung cancer incidence rates increased from 1975 to 2003, decelerating since 1991 and breast cancer incidence rates stabilized from 2001 to 2003. Latinos had lower incidence rates in 1999-2003 for most cancers, but higher rates for stomach, liver, cervix, and myeloma (females) than did non-Latino white populations. Latino children have higher incidence of leukemia, retinoblastoma, osteosarcoma, and germ-cell tumors than do non-Latino white children. For several common cancers, Latinos were less likely than non-Latinos to be diagnosed at localized stages. CONCLUSIONS: The lower cancer rates observed in Latino immigrants could be sustained by maintenance of healthy behaviors. Some infection-related cancers in Latinos could be controlled by evidence-based interventions. Affordable, culturally sensitive, linguistically appropriate, and timely access to cancer information, prevention, screening, and treatment are important in Latino outreach and community networks.     

Hormone replacement therapy, mammography screening and changing age-specific incidence rates of breast cancer: an ecological study comparing two European populations

Background In 2003, for the first time, US breast cancer incidence rates have fallen. Experts argue whether this is due to the reduced uptake of screening mammography or to lower use of Hormone Replacement Therapy (HRT). This study aims to disentangle the respective impact of screening and HRT on age-incidence rates and histology of breast cancer, by comparing two populations with comparably high levels of screening mammography, but with different prevalence of HRT. Methods We included all invasive breast cancers recorded at the Geneva cancer registry (n = 4,909) and the Netherlands Cancer Registry (n = 152,428) between 1989–2003. We compared age-specific incidence rates and trends in histological subtyping between the two populations. Results Between 1989–1991, incidence rates increased with age in both populations. In 2001–2003, women aged 60–64 years showed highest incidence rates in Geneva, while in the Netherlands incidence rates continued to increase with age. The annual increase in ductal cancer incidence was similar in the Netherlands (2.3%) and Geneva (2.5%), but the annual increase in lobular cancer was sharper in Geneva (10%) than in the Netherlands (5%). Conclusion The sharp differences in age distribution and histological subtyping of breast cancer between two European populations are not attributable to screening, since both populations have a high uptake of mammography screening. Since the prevalence of HRT use is very high in Geneva and rather low in the Netherlands, HRT may explain these discrepancies. However, other etiological factors and differences in histological assessment may also have played a role.     

International variation in the incidence of adult primary malignant neoplasms of the brain and central nervous system

We examined international variation in adult brain cancer incidence in 69 populations from a subset of cancer registries included in Cancer Incidence in Five Continents, Volume IX that met stringent quality standards. We grouped these populations into World Areas. Age-standardized incidence rates varied by World Area similarly for men and women and were highest in northern America non-Hispanic whites and Australians, followed closely behind by Europeans, then South Americans and northern America Hispanic whites. Rates among south-central Asians and northern America blacks were half to three-fifths the rates among northern America non-Hispanic whites. Rates among eastern and southeastern Asians and northern America Asians and Pacific Islanders were one-third to two-fifths the rates among northern America non-Hispanic whites. Incidence rates increased less steeply with age in the former two populations than in other populations. These results strongly suggest that populations of eastern and southeastern Asian origin, regardless of residence, have substantially lower brain cancer incidence rates than white populations, due to differences in genetic susceptibility and/or environmental/lifestyle exposures that persist in migrant populations. Male/female incidence rate ratios varied by age, but not by World Area, suggesting that this male/female difference is biologically based.     

Descriptive epidemiology of thyroid cancer in Hawaii

Data were analyzed from 1110 thyroid cancer cases between 1960 and 1984 identified by the Hawaii Tumor Registry, a population-based Statistics, Epidemiology and End Results (SEER) participant covering the entire state of Hawaii. Incidence rates for men and women were relatively stable during this 25-year period. The overall age-adjusted rates were 8.1 per 100,000 for women and 3.1 per 100,000 for men. There was a significant variation in incidence on the basis of ethnicity, with the highest rates for women occurring in Filipinos (18.2 per 100,000) and for men in Chinese (6.3 per 100,000). A comparison of different populations around the world showed that Hawaii has some of the highest reported incidence rates for thyroid cancer. In addition, a comparison of ethnic-specific incidence rates for groups living in Hawaii with people of the same ethnic backgrounds living in other geographic areas showed that Hawaii residents generally have much higher rates, suggesting that environmental influences are responsible for the unusually high rates in Hawaii.     

Differences in cancer incidence among Indians in Alaska and New Mexico and U.S. Whites, 1993-2002.

Cancer incidence for American Indians and Alaska Natives is typically reported as a single rate for all U.S. indigenous populations combined. Previously reported combined rates suggest that American Indians and Alaska Natives have lower cancer incidence rates compared with the U.S. population. Alaska Native people comprise three major ethnic groups: Eskimo, Indian, and Aleut people. We examined cancer incidence from only Alaska Indians and compared incidence rates with an American Indian population living in New Mexico. These data indicate striking differences in cancer patterns between two American Indian populations. Cancer data for the years 1993 to 2002 for American Indians of New Mexico and U.S. Whites are from the National Cancer Institute Surveillance, Epidemiology, and End Results Program Public-use data set. Data for Alaska Indians are from the Alaska Native Tumor Registry, which is also a Surveillance Epidemiology and End Results Program participant. Overall, cancer incidence rates for all sites combined in New Mexico Indian men and women were lower than U.S. White rates, whereas Alaska Indian men and women exceeded U.S. rates. In comparing Alaska and New Mexico Indians, we observed a 2.5-fold higher incidence of cancer among Alaska Indians. The largest differences between the two Indian populations were noted primarily in cancers associated with tobacco use, including cancers of the oral cavity/pharynx, esophagus (only in men), colon and rectum, pancreas, larynx (men), lung, prostate, and urinary bladder (men). Lung cancer rates in Alaska Indian men and women were 7 and 10 times those of New Mexico Indian men and women.     

Cancer among Haitians in Florida

Data on cancer rates from West Indian populations are scarce, and to the authors' knowledge there are no published data on cancer rates and distributions among Haitians. Proportional distributions of cancers among three groups of patients living in Florida were compared: Haitian born blacks, United States born blacks, and non-Haitian Caribbean born blacks. The incidence rate of cancer of the cervix among the Haitian and United States born black groups was also compared. Increased rates of certain malignancies associated with viral infection or immunodeficiency were found in the Haitian group. These tumors were hepatocellular carcinoma, nasopharyngeal carcinoma, reticulum cell sarcoma, Kaposi's sarcoma, and carcinoma of the uterine cervix. The age-adjusted incidence rate of carcinoma of the cervix was especially high among Haitian women even with a liberal estimate of the female Haitian population from whom the cases were drawn. Except for cancer of the cervix, the numbers of cancers of interest were small, and age-adjusted incidence rates were not calculated. Continued epidemiological study of larger numbers of patients is needed to evaluate these findings further.     

Changes in nonmelanoma skin cancer incidence between 1977-1978 and 1998-1999 in Northcentral New Mexico.

Nonmelanoma skin cancer (NMSC) is a highly common form of malignant disease in light-skinned populations. In 1977-1978, the National Cancer Institute sponsored a population-based skin cancer survey that found marked geographic variability in the incidence of NMSC within the United States. Some of the highest rates were observed in the southwestern state of New Mexico within its non-Hispanic white population. We recently undertook a follow-up survey of NMSC in New Mexico and report here incidence rate data for non-Hispanic white residents of a three-county area in northcentral New Mexico for two 12-month time periods: June 1, 1977 to May 31, 1978 and July 1, 1998 to June 31, 1999. Our results show that incidence rates of basal cell carcinoma increased by 50% in males and 20% in females, whereas rates of squamous cell carcinoma roughly doubled in both males and females. Temporal analysis of rates according to major anatomical site showed the head and neck was consistently the most frequent site of occurrence, however, the greatest percentage increase in rates over time occurred at the upper and lower limbs. These findings are consistent with those reported for various other populations showing the incidence of NMSC has measurably increased since the 1970s.     

Cancer incidence by marital status: U.S. Third National Cancer Survey.

Site-specific cancer incidence rates were computed by sex, age, and marital status for whites and blacks separately for ages 35-64 years with the use of population-based incidence data from the Third National Cancer Survey (1969-71) and with demographic data from the 1970 U.S. Census. Although rates were presented for all cancer sites combined and for 44 specific sites or rubrics, discussion focused on the 17 most common cancers. Within age, race, and sex groups, patterns of cancer incidence by marital status were compared by means of standardized incidence ratios, and the consistency of marital status patterns across age groups was assessed statistically. Among the most notable findings were: excess cancer rates across most sites and age groups in single black males, consistently high rates for cancer of the lung and bronchus in divorced white males and in single black females, low rates for the hormone-dependent reproductive tumors (prostate gland, breast, uterine corpus, and ovary) in separated white males and females, and high rates for cervical cancer among separated white women. Marital status patterns, where found, frequently differed between whites and blacks and between males and females.     

Invasive breast cancer incidence trends by detailed race/ethnicity and age

Racial/ethnic disparities in breast cancer incidence may contain important evidence for understanding and control of the disease. Monitoring the incidence trends of breast cancer by race/ethnicity allows identification of high risk groups and development of targeted prevention programs. Using population-based cancer registry data from the Los Angeles Cancer Surveillance Program, we examined the invasive female breast cancer incidence trends among the diverse racial/ethnic populations in Los Angeles County, California, from 1972 to 2007. Age-adjusted incidence rates (AAIRs) and age-specific incidence rates (ASIRs) were calculated and examined respectively for non-Hispanic (NH) white, black, Hispanic, Chinese, Filipina, Japanese and Korean women by calendar year and time period. Rising trends of AAIRs were found in all racial/ethnic groups during the 1980s and 1990s. The breast cancer risk increased more substantially in Japanese and Filipinas than in Chinese and Koreans. During 2000-2007, the trends of AAIRs declined significantly among NH white women and slightly in blacks, remained unchanged for Hispanics and continued to rise significantly among all Asian subgroups. The patterns of ASIRs by race/ethnicity changed dramatically over time. By 2000-2007, younger Hispanic women had the lowest breast cancer risk, replacing the Chinese and Koreans who formerly had the lowest risk. Rapidly increasing breast cancer incidence trends among Asian-Americans underline the importance of behavioral and lifestyle changes as a result of acculturation on the development of the disease. The unique trends of breast cancer incidence by race/ethnicity suggest the need for targeted breast cancer control programs for different racial/ethnic populations.     

Mortality and cancer incidence in 263 patients with ataxia-telangiectasia

Mortality and cancer incidence were measured retrospectively in 263 ataxia-telangiectasia (A-T) homozygotes. For white and black A-T patients, respectively, all-cause mortality was 50 and 147 times higher than expected based on U.S. mortality rates. There were 52 primary cancers, representing a 61-fold cancer excess for white probands and a 184-fold excess for black probands. The cancer excess was most pronounced for lymphoma, with 252- and 750-fold excesses observed for whites and blacks, respectively. All the age-specific mortality and cancer incidence rates for blacks exceeded those for whites, and overall mortality was 3.0 times higher for black probands than for whites (P less than .001), whereas cancer incidence was 2.2 times higher (P less than .06). Among the white A-T patients, 36% of those who had died had lived at least until 20 years of age, and 33% of those still living were at least 20 years old.     

Rapidly rising breast cancer incidence rates among Asian-American women

In recent years, breast cancer incidence rates have fluctuated over relatively short time spans; examination of these patterns can provide etiologic clues and direction for prevention programs. Asian-American women are generally considered to be at lower risk of breast cancer than other ethnic groups. However, their rates are typically based on an aggregation of ethnic Asian populations, which may obscure important ethnic differences in risk. Detailed analyses of the trends in ethnic-specific incidence rates will provide more information than when ethnicities are combined. Los Angeles County, California, the most populous and probably the most ethnically diverse county in the United States, has a large multi-ethnic Asian-American population. Trends in invasive female breast cancer incidence were examined using data from the Los Angeles Cancer Surveillance Program, the population-based cancer registry covering the County. Although overall breast cancer incidence rates remained stable in the late 1980s and early 1990s, data for the most recent 5-year period suggest that incidence may again be increasing for Asian-American and non-Hispanic white women over age 50 (estimated annual percent change = 6.3%, p < 0.05 and 1.5%, p < 0.05, respectively), although little change has occurred among black and Hispanic women. Invasive breast cancer incidence rates for Asian-American ethnic groups are heterogeneous and, for most, are increasing. In Los Angeles County, rates for Japanese-American women have increased rapidly since 1988 and are now approaching rates for non-Hispanic white women. Rates among Filipinas, who have historically had higher rates than their other Asian-American counterparts, are not increasing as rapidly as rates for Japanese women, but remain relatively high. Breast cancer risk among women of Japanese and Filipino ancestry is twice that of Chinese and Korean women. Asian women, who commonly have low breast cancer rates in their native countries, typically experience increasing breast cancer incidence after immigrating to the United States. Ethnic-specific incidence rates show that Japanese-Americans, the first Asian population to immigrate to Los Angeles County in large numbers and the most acculturated, have experienced a rapid increase in breast cancer incidence. Japanese-American rates in Los Angeles County may have already surpassed those of non-Hispanic whites if recent trends have continued unabated.     

Cancer in the population of Hanoi, Vietnam, 1988-1990.

The first results from the population-based cancer registry for the city of Hanoi, in northern Vietnam, are presented. In men, incidence rates are moderate-low with the most common cancers being lung, stomach and liver. Cancer of the penis, reportedly very common in early case series from Vietnam, is now rarely seen. In women, incidence rates are low with the most common cancer, breast cancer, having a recorded incidence similar to that in China. Cervix cancer incidence is very low, which contrasts strongly with hospital series from the south of Vietnam, and of 30 years earlier in Hanoi. The incidence of choriocarcinoma is high, and that of nasopharynx cancer (in both sexes) moderately so; both findings are typical of southeast Asian populations. The incidence rates are coherent with the results from recent studies of Vietnamese migrants in the USA and UK.     

Recent changes in breast cancer incidence and risk factor prevalence in San Francisco Bay area and California women: 1988 to 2004

Introduction  

Historically, the incidence rate of breast cancer among non-Hispanic white women living in the San Francisco Bay area (SFBA) of California has been among the highest in the world. Substantial declines in breast cancer incidence rates have been documented in the United States and elsewhere during recent years. In light of these reports, we examined recent changes in breast cancer incidence and risk factor prevalence among non-Hispanic white women in the SFBA and other regions of California.     

Preventable breast cancer is postmenopausal

Breast cancer incidence has markedly increased in Western countries for reasons that are not entirely understood. We characterized periodic and age-specific incidence trends of breast cancer in immigrants who migrated from low incidence areas to Sweden. The incidence in immigrants was compared to that in native Swedes and standardized incidence ratios (SIRs) were calculated, based on the Swedish Family-Cancer Database. Age-specific incidence data for low and high incidence populations were obtained from Cancer Incidence in Five Continents IX and NORDCAN. For immigrants from the seven lowest countries/regions 535 breast cancers were identified; the SIRs ranging from 0.45 for Turkish to 0.70 for Greek women. The SIR increased somewhat with the length of stay in Sweden, from 0.55 for stay between 0 and 10 years to 0.59 for a stay of 20+ years. The age-specific incidence curves for these immigrants were superimposable upon the earliest Swedish (year 1960) or Danish (1943) rates. These rates differed from the current Swedish rates by a much lower postmenopausal component. Large incidence differences were also observed between white Californians and immigrants from China and Korea. Our results show that the main difference between high and low incidence areas is in postmenopausal cancer which has increased preferentially during the past century. Immigrants from low risk areas to Sweden show age-specific incidence patterns of Swedes half a century ago. These differences offer opportunities for the identification of factors underlying breast cancer etiology and tools for prevention.