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Objectives.This is the second of 2 papers reporting on the result of the Circumpolar Inuit Cancer Review, an international collaborative effort involving researchers and health officials from Alaska, Canada and Greenland.Methods.Inuit cancer cases by age-sex group and anatomic site were obtained from the regional cancer registries. Results. Cancer in general is increasing among Inuit, in all regions, and among both men and women. Inuit continue to be at extreme high risk, relative to non-Inuit and to comparisons of global populations, for the historically recognized so-called traditional cancers (such as cancer of the nasopharynx and salivary glands). Among the so-called modern cancers prevalent in developed societies, lung cancer is rapidly increasing in incidence (especially in Canada), such that the rate in both Inuit men and women is the highest in the world; other cancers, such as colorectal cancer, are also on the rise (especially in Alaska), while breast and prostate cancer remain low relative to the non-Inuit population. The decline in cervical cancer is a positive development; in the 3 regions, the rate in Greenland is the highest.Conclusions.Data such as these can form the basis of interventions directed towards known risk factors such as smoking, diet, obesity, viral and bacterial infections, and low screening prevalence. Cancer surveillance is a basic task of the public health system; in the Arctic, it is particularly important as Inuit continue to undergo further changes in their life-styles and social environments.

Objectives.This is first of 2 papers on the Circumpolar Inuit Cancer Review, an international collaborative effort involving researchers and health officials from Alaska, Canada and Greenland. It covers the period 1989–2003, updating the last review (1969-1988) and together provides an overview of the trends and patterns of cancer among the Inuit in 3 countries and over a 35-year period.Methods.Inuit cancer cases by age-sex group and anatomic site were obtained from the regional cancer registries. The sources of the age-sex distribution of various Inuit populations include the population registry (Greenland), and annual estimates and periodic censuses (Alaska and Canada). Incidence rates were age-standardization by the direct method to the standard world population of the International Agency for Research on Cancer.Conclusions.This project demonstrates the feasibility of international partnerships in cancer surveillance, and when these partnerships are extended to other diseases and health conditions, they can contribute to the development of a Circumpolar Health Observatory.

Objectives. The incidence of prostate cancer differs significantly between US race groups. In prior reviews of cancer in Alaska Natives, the incidence of prostate cancer has been observed to occur at a low rate compared to US Whites and Blacks. However, a detailed report of prostate cancer in this population has not been previously published.Study Design. Incidence of prostate cancer in Alaska Native men was determined for the time period 1969–2003 using data from the Alaska Native Tumor Registry. The registry is a population-based registry which participates in the National Cancer Institute Surveillance, Epidemiology and End Results Program, and has collected cancer information on Alaska Natives since 1969.Methods. Incidence rates were calculated for all Alaska Natives and for each of the three major ethnic groups (Aleut, Eskimo, Indian). Comparisons of incidence rates between Alaska Natives and US Whites were performed using odds ratios. Temporal changes were identified by a Chi square analysis for trend.Results. During the 35-year period of review, 332 Alaska Native men were diagnosed with prostate cancer. The age-adjusted incidence rate of 69.5 per 100 000 in Alaska Native men during 1994–2003 was significantly higher than the rate of 45.5 per 100 000 for the earlier period 1969-1983. The US White rate for 1994-2002 of 169.5 per 100 000 was significantly higher than the rate for Alaska Native men for 1994-2003. Results of comparisons between Alaska Native ethnic groups for 1969-2003 showed that prostate cancer was highest in Indians and Aleuts and lowest among Eskimos.Conclusions. Compared to the US White population, the incidence of prostate cancer in Alaska Native men is significantly lower. Prostate cancer rates among Alaska Native ethnic groups differ. The reason for these differences remains undetermined.

Objectives. To determine if an increased rate of breast cancer in Alaska Native women is related to their consumption of a subsistence diet that may contain p, p’-dichlorodiphenylethylene (DDE) and polychlorinated biphenyls (PCBs).Study Design. A retrospective case control design.Methods. We analyzed banked serum collected between 1981 and 1987 from 126 Alaska Native women, including 63 case women who subsequently developed breast cancer and 63 age-matched control women who remained cancer-free. Serum was analyzed for DDT, DDE, 13 other chlorinated pesticides, and 28 PCB congeners.Results. The geometric mean for p, p’-DDE levels among case women was 8.67 ppb (95% Confidence Interval 7.48, 10.04); among control women, the geometric mean was 7.36 ppb (6.53, 8.30). The geometric mean for total PCB levels among case women was 4.55 ppb (3.61, 5.74) and for control women, the geometric mean was 6.10 ppb (4.73, 7.86). Cancer status and total PCB levels varied across ethnicity (i.e., Eskimo, Aleut, and Indian) but DDE levels were uniform among these ethnic groups. Using conditional logistic regression analysis to adjust for potential confounders (e.g., ethnicity, family history of breast cancer, parity), we found an odds ratio of 1.43 (0.46, 4.47) for the highest tertile of DDE exposure and 0.42 (0.07, 2.38) for the highest tertile of total PCB exposure.Conclusions. Although the results are limited by small sample size and restricted risk factor information, our findings of higher DDE levels, but lower PCB levels among women with breast cancer are consistent with previous research. Our results confirm exposure to organochlorines among Alaska Native women but do not identify these exposures as a significant risk factor for breast cancer.

ABSTRACTObjectives: To report the levels of DDT, DDE, other chlorinated pesticides, and PCBs found in 131 Alaska Native women who had serum samples collected between 1980 and 1987 and to compare these levels to other published studies of DDE and PCB exposure among U.S. women.Study Design: Review of data collected during a case-control study of the relationship between organochlorine chemicals and breast cancer. Data for case and control women were pooled in this analysis because case-control differences were found to be minimal and because serum samples pre-dated cancer diagnoses by 3 to 10 years.Results: More than 99% of the women had detectable levels of p,p-DDE (mean 9.10 ng/mL or ppb). Mean total PCB level was 7.56 ppb. Levels of exposure varied by geographical location and ethnic identification, which may be a reflection of dietary differences. Five of the organochlorines were detected in at least half of the study population. Results were recalculated using detection limits corresponding to other published studies of DDE and PCB levels in U.S. women. Alaska women had levels similar to those reported from New York women collected in the 1980s. We compared the PCB congener levels measured in Alaska Native women with levels reported in Arctic animals and found similar PCB congener profiles. The six most frequently detected contaminants in Alaska Natives were also detected in the marine mammal samples reported by Becker et al (5).Conclusions: Our study identified widespread Alaska Native exposure to organochlorines that originated outside of the Arctic, a finding also seen in other studies. Our results provide a reference baseline for exposure levels during the 1980s, but further research is necessary to assess temporal trends in exposure among Alaska Natives. Further, the need for national and international inter-laboratory standardization for testing for persistent organochlorines to facilitate comparisons between Alaska Natives and other American populations is clearly demonstrated. (Int J Circumpolar Health 2001; 60: 157-169)