Department of Biostatistics, İstanbul Aydın University, İstanbul, Turkey
Department of Population Medicine, College of Medicine, QU Health, Qatar University, Doha, Qatar
Balkan Med J. 2022 Nov 7;39(6):429-435. doi: 10.4274/balkanmedj.galenos.2022.2022-5-54. Epub 2022 Oct 26.
Reports on the risk and prognosis of breast cancer in relation to the sex of a child have been conflicting. Since medical sciences play an important role in informing sociocultural understandings of health and illness, evidence-based studies have the potential to foster or counter stigma and shape social attitudes toward a newborn’s sex.
To pool all available evidence to provide the highest level of evidence on the association between the sex of the first child and breast cancer risk or prognosis.
Systematic review and meta-analyses.
A comprehensive search using three databases was conducted from inception until May 2020. Titles and abstracts of all papers identified were independently screened by two authors. Data extraction and quality assessment were also performed independently by two researchers. The breast cancer risk was quantified using the odds ratio, and the prognosis (i.e., mortality) was measured using the risk ratio.
In the meta-analysis, 11 studies with more than 1 million participants were included. The pooled estimate from the five studies on risk and the six studies on prognosis were odds ratio 0.99 (95% confidence interval, 0.95-1.03) and risk ratio 1.00 (95% confidence interval, 0.80-1.26), respectively.
When we pooled all available evidence, the sex of the firstborn child was neither associated with risk nor prognosis in breast cancer. Clinically, our findings are reassuring and important, especially in light of previous studies that recommended differential treatment and counseling based on the sex of the first child. Socially, our findings challenge conventional social stereotypes that regard male children as biologically superior to female children.
关于儿童性别与乳腺癌风险和预后的关系的报告结果相互矛盾。由于医学科学在告知社会文化对健康和疾病的理解方面发挥着重要作用，因此基于证据的研究有可能助长或抵制耻辱感，并塑造社会对新生儿性别的态度。
汇总所有现有证据，为第一胎子女性别与乳腺癌风险或预后之间的关联提供最高水平的证据。
系统评价和荟萃分析。
从创建数据库开始，到 2020 年 5 月，我们使用三个数据库进行了全面搜索。两名作者独立筛选所有论文的标题和摘要。两名研究人员还独立进行了数据提取和质量评估。使用比值比量化乳腺癌风险，使用风险比测量预后（即死亡率）。
荟萃分析纳入了 11 项超过 100 万参与者的研究。五项关于风险的研究和六项关于预后的研究的汇总估计值分别为比值比 0.99（95%置信区间，0.95-1.03）和风险比 1.00（95%置信区间，0.80-1.26）。
当我们汇总所有现有证据时，第一胎子女的性别与乳腺癌的风险或预后均无关联。从临床角度来看，我们的研究结果令人放心且非常重要，尤其是考虑到先前的研究建议根据第一胎子女的性别进行差异化治疗和咨询。从社会角度来看，我们的研究结果挑战了认为男童在生物学上优于女童的传统社会刻板印象。
