Publications by authors named "Kirsti Vik Hjerkind"

Purpose: The stage-specific survival of young breast cancer patients has improved, likely due to diagnostic and treatment advances. We addressed whether survival improvements have reached all socioeconomic groups in a country with universal health care and national treatment guidelines.

Methods: Using Norwegian registry data, we assessed stage-specific breast cancer survival by education and income level of 7501 patients (2317 localized, 4457 regional, 233 distant and 494 unknown stage) aged 30-48 years at diagnosis during 2000-2015.

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Background: Women with high socioeconomic status (SES) have the highest incidence rates of breast cancer. We wanted to determine if high SES women only have higher rates of localized disease, or whether they also have higher rates of non-localized disease. To study this, we used data on a young population with universal health care, but not offered screening.

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Background: Lifestyle factors are associated with overall breast cancer risk, but less is known about their associations, alone or jointly, with risk of specific breast cancer subtypes.

Methods: We conducted a case-control subjects study nested within a cohort of women who participated in the Norwegian Breast Cancer Screening Program during 2006-2014 to examine associations between risky lifestyle factors and breast cancer risk. In all, 4402 breast cancer cases subjects with information on risk factors and hormone receptor status were identified.

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Background: Fully automated assessment of mammographic density (MD), a biomarker of breast cancer risk, is being increasingly performed in screening settings. However, data on body mass index (BMI), a confounder of the MD-risk association, are not routinely collected at screening. We investigated whether the amount of fat in the breast, as captured by the amount of mammographic non-dense tissue seen on the mammographic image, can be used as a proxy for BMI when data on the latter are unavailable.

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Bakgrunn: Befolkningssammensetningen i Norge har endret seg, og innvandrere utgjør nå nær 14 % av befolkningen. Vi vet ikke hvordan dette påvirker kreftbildet. I denne studien presenterer vi forekomst av kreft for den norskfødte delen av befolkningen for å kunne få et bilde på hvordan forekomsten har endret seg, sett bort fra effekten av innvandring.

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Age and tumor subtype are prognostic factors for breast cancer survival, but it is unclear which matters the most. We used population-based data to address this question. We identified 21,384 women diagnosed with breast cancer at ages 20-89 between 2005 and 2015 in the Cancer Registry of Norway.

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Volumetric mammographic density (VMD) measures can be obtained automatically, but it is not clear how these relate to breast cancer risk factors. The cohort consisted of 46,428 women (ages 49-71 years) who participated in BreastScreen Norway between 2007 and 2014 and had information on VMD and breast cancer risk factors. We estimated means of percent and absolute VMD associated with age, menopausal status, body mass index (BMI), and other factors.

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To what extent alcohol, smoking, and physical activity are associated with the various subtypes of breast cancer is not clear. We took advantage of a large population-based screening cohort to determine whether these risk factors also increase the risk of the poor prognosis subtypes. We conducted a matched case-control study nested within the Norwegian Breast Cancer Screening Program during 2006-2014.

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Background: Physical activity may counteract the adverse effects of adiposity on cardiovascular mortality; however, the evidence of a similar effect on diabetes is sparse. This study examines whether physical activity may compensate for the adverse effect of adiposity on diabetes risk.

Methods: The study population consisted of 38 231 individuals aged 20 years or more who participated in two consecutive waves of the prospective longitudinal Nord-Trøndelag Health Study in Norway: in 1984-1986 and in 1995-1997.

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