Heting Mei, Wenping Lu, Yanan Wang, Dongni Zhang, Xiaoqing Wu, Zhli Zhuo
Guang'anmen Hospital of Chinese Academy of Chinese Medical Sciences, Beijing, 100053, China.
Heliyon. 2023 Mar 22;9(4):e14733. doi: 10.1016/j.heliyon.2023.e14733. eCollection 2023 Apr.
Levonorgestrel intrauterine sustained release system (LNG-IUS) is an intrauterine hormonal contraceptive device. Breast cancer (BC) was the most common type of cancer in women in the world in 2020. The relationship between LNG-IUS and BC is controversial We conducted an updated meta-analysis (larger sample capacity and including Asian data) to explore whether LNG-IUS can increase the risk of BC.
We performed a thorough review of peer-reviewed publications from January 2005 through November 2022 using combinations of search terms for BC risk and LNG-IUS in the PubMed, Cochrane, Embase, Science Direct, and Web of Science databases. Studies reporting BC risk estimates among users of LNG-IUS were included according to the PRISMA criteria. Two authors independently evaluated all studies identified from the databases using Endnote software, and a third author resolved disagreements. The quality of evidence was evaluated using the Newcastle‒Ottawa Scale (NOS). A funnel plot was generated to assess publication bias.
We identified 3029 studies; 12 studies were included in our systematic review, and 6 studies involving 261,221 women were included in our meta-analysis. Two subgroup analyses were performed for different study designs. A total of 190,475 women were included in the meta-analysis of cohort studies, and the results were RR = 0.80 (95% CI 0.57-1.11, Z = 1.33, P = 0.18 > 0.05). The meta-analysis of the case‒control studies included 70,746 women, and the results were OR = 1.38 (95% CI 0.98-1.94, Z = 1.85, P = 0.06 > 0.05).
Evidence of an increased risk of BC was not observed among LNG-IUS users.
There are inconsistencies in existing studies that prevent us from confirming whether LNG-IUS can increase the risk of BC. Our updated meta-analysis preliminarily suggested that LNG-IUS did not increase the risk of BC, providing evidence for more clinically safe use and thus providing a better choice for contraception.
左炔诺孕酮宫内缓释系统（LNG-IUS）是一种宫内激素避孕装置。乳腺癌（BC）是2020年全球女性中最常见的癌症类型。LNG-IUS与BC之间的关系存在争议。我们进行了一项更新的荟萃分析（样本量更大且纳入了亚洲数据），以探讨LNG-IUS是否会增加BC的风险。
我们使用PubMed、Cochrane、Embase、Science Direct和Web of Science数据库中BC风险和LNG-IUS的搜索词组合，对2005年1月至2022年11月期间经过同行评审的出版物进行了全面回顾。根据PRISMA标准纳入报告LNG-IUS使用者中BC风险估计值的研究。两位作者使用Endnote软件独立评估从数据库中识别出的所有研究，第三位作者解决分歧。使用纽卡斯尔-渥太华量表（NOS）评估证据质量。生成漏斗图以评估发表偏倚。
我们识别出3029项研究；12项研究纳入我们的系统评价，6项涉及261,221名女性的研究纳入我们的荟萃分析。针对不同研究设计进行了两项亚组分析。队列研究的荟萃分析共纳入190,475名女性，结果为RR = 0.80（95%CI 0.57 - 1.11，Z = 1.33，P = 0.18 > 0.05）。病例对照研究的荟萃分析纳入70,746名女性，结果为OR = 1.38（95%CI 0.98 - 1.94，Z = 1.85，P = 0.06 > 0.05）。
未观察到LNG-IUS使用者中BC风险增加的证据。
现有研究存在不一致性，使我们无法确定LNG-IUS是否会增加BC的风险。我们更新的荟萃分析初步表明，LNG-IUS不会增加BC的风险，为更安全的临床使用提供了证据，从而为避孕提供了更好的选择。
