Cancer among the circumpolar Inuit, 1989-2003. I. Background and methods.

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.

Cancer among the circumpolar Inuit, 1989-2003. II. Patterns and trends.

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.

Evaluation of a convenient enzyme immunoassay to assess the quality of genital specimens submitted for the detection of human papillomavirus DNA by consensus PCR.

BACKGROUND: In the PGMY-line blot assay, a human beta-globin fragment is co-amplified with human papillomavirus (HPV) DNA, and both analytes are detected by hybridization with probes fixed on a strip in a linear array. The beta-globin DIG-MWP test also detects beta-globin amplicons, but in a microtiter plate-based enzyme immunoassay format. Although the PGMY-line blot assay detected 50 cells per test, the beta-globin DIG-MWP test generated a signal above the detection cut-off with five cells per test. OBJECTIVE: The performance of the beta-globin DIG-MWP assay to detect beta-globin DNA was assessed. STUDY DESIGN: The beta-globin DIG-MWP assay was compared to a standard beta-globin PCR and to the PGMY-line blot strips on 401 genital specimens. Overall, the three beta-globin assays were compared on 325 undiluted lysates, 14 diluted lysates and DNA extracted from 62 lysate samples. RESULTS: Concordance between the PGMY-line blot and the standard beta-globin assay reached 99.5% (399 of 401 results), for a kappa value of 0.95. Concordant results were also obtained between the beta-globin DIG-MWP assay and PGMY-line blot assay for 387 (96.5%) of 401 test results, for a kappa value of 0.57. Discordant results were due to the increased sensitivity of the DIG-MWP assay. Using a cut-off for positivity at 1.500 optical density (OD) units for beta-globin DIG-MWP, concordance improved to 100% (401 of 401 results, kappa at 1.00). CONCLUSION: The beta-globin DIG-MWP assay was adequate to screen for sample adequacy for HPV analysis in genital specimens.

Human papillomavirus and cervical dysplasia in Nunavut: prelude to a screening strategy.

OBJECTIVES: To determine the prevalence of oncogenic human papillomavirus' (HPV) in Nunavut and to assess the association between HPV and squamous intraepithelial lesions (SIL) as a prelude to planning a better screening strategy. STUDY DESIGN: A cross-sectional study was conducted on the Pap-screened populations in 19 communities in Nunavut, Canada. SIL was determined using Liquid-based cytology, and HPV testing was done using the Hybrid Capture II assay. RESULTS: Prevalence of oncogenic HPVs in 1,290 women ages 13-79 was 26% and of Cervical Dysplasia was 7.2%. Over 90% of women with SIL had positive HPV tests. Over 75% of women who were HPV positive but SIL negative were under 30 years of age. CONCLUSION: Consideration should be given to using liquid-based cytology for Pap testing. Also consider concurrent HPV testing in those over 30 years old and reflex testing of HPV in those under 30 years old with a positive HPV test.