Relationship between selenium and breast cancer: a case-control study in the Klang Valley.

Introduction: The purpose of this study was to assess the relationship between selenium status and intake among breast cancer patients from the Klang Valley.

Methods: 64 cases and 127 controls were matched for age (range 30-65 years) and ethnicity, with an 80 percent study power. Subjects were interviewed to obtain information on their habitual dietary intakes, demographic data and medical history.

Antioxidant intake and status, and oxidative stress in relation to breast cancer risk: a case-control study.

A case control study was carried out to investigate associations between breast cancer risk, antioxidant status and oxidative stress among women in Klang Valley and Selangor. A total of 57 newly diagnosed cases aged 30 to 66 years old participated and were matched for age and ethnicity with 139 controls with no diagnosis of cancer or other chronic diseases. An interview based questionnaire designed to collect information on demographic and socioeconomic status, as well as reproductive, medical and dietary history was used.