Department of Surgery, Skåne University Hospital Malmö, Lund University, Malmö, Sweden.
Division of Oncology and Pathology, Department of Clinical Sciences, Lund University, Lund, Sweden.
Cancer Epidemiol Biomarkers Prev. 2020 Jul;29(7):1335-1340. doi: 10.1158/1055-9965.EPI-20-0122. Epub 2020 May 26.
Iodine has been suggested to protect against breast cancer, but there are no epidemiologic studies on individual risk. An interesting finding is that in areas where the exposure to both selenium and iodine are high (e.g., Japan), the risk of breast cancer is lower than in areas where selenium is high and iodine low (e.g., United States), or in areas where both are low (e.g., Northern Europe). The aim of this study was to investigate the association between prediagnostic serum iodine levels and subsequent breast cancer risk, and to investigate if this potential association was modified by selenium levels.
The Malmö Diet and Cancer Study provided prediagnostic serum samples and the current analysis included 1,159 breast cancer cases and 1,136 controls. Levels of baseline serum iodine and selenium were analyzed. A logistic regression analysis yielded ORs with 95% confidence intervals adjusted for potential confounders.
There was no evidence of an overall association between iodine levels and risk of breast cancer. Among women with high selenium levels (above the median), high iodine levels were associated with a lower risk of breast cancer; the OR for above versus below the median was 0.75 (0.57-0.99). The corresponding OR for women with low selenium was 1.15 (0.87-1.50), and the was 0.06.
The combination of high serum iodine levels and high selenium levels was associated with a lower risk of breast cancer.
A high iodine and selenium exposure may decrease the risk of breast cancer.
碘已被认为可以预防乳腺癌，但目前尚无关于个体风险的流行病学研究。一个有趣的发现是，在暴露于高碘和高硒的地区（例如日本），乳腺癌的风险低于暴露于高硒低碘的地区（例如美国），或暴露于两者都低的地区（例如北欧）。本研究旨在探讨诊断前血清碘水平与随后乳腺癌风险之间的关系，并探讨这种潜在的关联是否受硒水平的影响。
马尔默饮食与癌症研究提供了诊断前的血清样本，本分析包括 1159 例乳腺癌病例和 1136 例对照。分析了基线血清碘和硒的水平。逻辑回归分析得出了调整潜在混杂因素后的 OR 值及其 95%置信区间。
碘水平与乳腺癌风险之间没有总体关联的证据。在高硒水平（高于中位数）的女性中，高碘水平与乳腺癌风险降低相关；高于中位数与低于中位数的比值比为 0.75（0.57-0.99）。相应的低硒比值比为 1.15（0.87-1.50），P 值为 0.06。
高血清碘水平和高硒水平的结合与乳腺癌风险降低相关。
高碘和高硒暴露可能降低乳腺癌的风险。
