Fish consumption in relation to breast cancer: A case-control study

Abstract

Background: Even though regular fish consumption is highly recommended to reduce the risk of developing several cancers, available evidence on the association between breast cancer and fish is inconclusive. We aimed to explore the association between fish consumption and breast cancer in a well-characterized population of Iranian women. Methods: This study enrolled 350 newly diagnosed stage I-IV breast cancer patients and 700 cancer-free controls living in Isfahan. Controls had no family history of breast cancer and were matched to cancer patients in term of age and socioeconomic status (SES). Dietary intakes were determined using a validated food frequency questionnaire (DS-FFQ). In addition, data on potential confounding factors were collected using pre-tested questionnaires. Results: After adjusting for potential confounders, women in the highest quartile of fish consumption had a lower odds of breast cancer than those in the lowest quartile (OR: 0.57, 95% CI: 0.34-0.95). The stratified analysis by menopausal status revealed an inverse association in postmenopausal women (OR: 0.53, 95% CI: 0.30-0.94). Conclusions: Our findings suggest higher fish consumption is associated with a lower likelihood of having breast cancer, particularly in post-menopause. The findings should be interpreted with caution due to the case-control study design. To further examine this association, prospective studies are needed.