Department of Cancer Biomedical Science, National Cancer Center Graduate School of Cancer Science and Policy, 323 Ilsan-ro, Ilsandong-gu, Goyang, Gyeonggi-do 10408, Republic of Korea.
Division of Cancer Epidemiology and Management, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang, Gyeonggi-do 10408, Republic of Korea.
Carcinogenesis. 2021 Oct 26;42(10):1260-1269. doi: 10.1093/carcin/bgab074.
Previous observational epidemiological studies have reported inconsistently the association between night shift work (NSW) and the risk of breast cancer (BC). This study aimed to investigate those associations by using a meta-analysis of observational epidemiological studies. We searched PubMed and EMBASE using keywords related to this topic from inception till November 2020. The pooled effect sizes such as odds ratio (OR), hazard ratio (HR) or relative risk (RR) with 95% confidence interval (CI) were calculated using a random-effects model. In the meta-analysis of a total of 32 observational studies including 13 case-control studies, 4 nested case-control studies and 15 cohort studies, NSW significantly increased the risk of BC (OR/RR/HR, 1.11; 95% CI, 1.04-1.20; I2 = 72.4%). In the subgroup meta-analysis by type of study, NSW was also associated with the increased risk of BC in case-control studies (OR, 1.34; 95% CI, 1.17-1.53; I2 = 63.8%). However, no significant association was found in both nested case-control studies (OR, 1.14; 95% CI, 0.89-1.46; I2 = 65.8%) and cohort studies (RR/HR, 0.98; 95% CI, 0.93-1.03; I2 = 25.3%). Besides, there was no significant association between NSW for over 20 years and the risk of BC (OR/RR/HR, 1.03; 95% CI, 0.95-1.11; I2 = 36.6%, n = 14). Given that cohort studies provide higher evidence than case-control studies, there is no association between NSW and the risk of BC.
先前的观察性流行病学研究对夜班工作（NSW）与乳腺癌（BC）风险之间的关联报告结果不一致。本研究旨在通过对观察性流行病学研究的荟萃分析来研究这些关联。我们使用与该主题相关的关键字在 PubMed 和 EMBASE 中进行了搜索，检索时间从建库起至 2020 年 11 月。使用随机效应模型计算汇总效应大小，如比值比（OR）、风险比（HR）或相对风险（RR）及其 95%置信区间（CI）。在总共 32 项观察性研究的荟萃分析中，包括 13 项病例对照研究、4 项巢式病例对照研究和 15 项队列研究，NSW 显著增加了 BC 的风险（OR/RR/HR，1.11；95%CI，1.04-1.20；I2 = 72.4%）。在按研究类型进行的亚组荟萃分析中，NSW 也与病例对照研究中 BC 风险的增加相关（OR，1.34；95%CI，1.17-1.53；I2 = 63.8%）。然而，在巢式病例对照研究（OR，1.14；95%CI，0.89-1.46；I2 = 65.8%）和队列研究（RR/HR，0.98；95%CI，0.93-1.03；I2 = 25.3%）中未发现显著相关性。此外，NSW 超过 20 年与 BC 风险之间也没有显著关联（OR/RR/HR，1.03；95%CI，0.95-1.11；I2 = 36.6%，n = 14）。鉴于队列研究提供的证据比病例对照研究更高，因此 NSW 与 BC 风险之间没有关联。
