Research question

What is relationship between unexplained recurrent pregnancy loss (RPL) and risk of cancer morbidity?

Design

A retrospective observational cohort study was conducted, based on data from a tertiary medical centre. RPL cases (exposed) were defined as women presenting with three or more unexplained confirmed pregnancy losses at 5–24 weeks, whose first visit to the RPL clinic was between 1990 and 2010. The unexposed group included women giving birth who were not RPL patients; these were matched by age and year of giving birth/admission (1:5 ratio). Data from the RPL and the live birth registries were cross-linked to the Israeli national cancer registry according to the unique ID number and merged into one database.

Results

The study group comprised 937 RPL patients who were matched by maternal age (P = 1.0) and admission date (P = 0.84) to 4685 women achieving a live birth. There was no difference in overall cancer incidence between groups (adjusted odds ratio [OR] 0.76, 95% confidence interval [CI] 0.55–1.03; P = 0.08). The secondary RPL group showed a trend towards decreased cancer morbidity incidence compared with primary RPL (adjusted OR 0.65, 95% CI 0.41–1.03; P = 0.07). Analysis by cancer type showed a similar risk for breast cancer among women with RPL compared with live birth, but a significantly lower risk for gynaecological cancers among women with RPL (adjusted OR 0.25, 95% CI 0.08–0.79; P = 0.018).

Conclusions

Unexplained RPL may be related to a lower risk of gynaecological cancers, possibly explained by hyper-responsive immunological mechanisms involving uterine natural killer cells.

中文翻译：

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复发性流产妇女的癌症诊断：一项回顾性队列研究

研究问题

原因不明的复发性流产 (RPL) 与癌症发病率之间有什么关系？

设计

基于来自三级医疗中心的数据，进行了一项回顾性观察性队列研究。RPL 病例（暴露）被定义为在 5-24 周内出现 3 次或更多不明原因的确诊流产的女性，她们第一次到 RPL 诊所就诊是在 1990 年至 2010 年之间。未暴露组包括非 RPL 患者的分娩女性；这些都与年龄和分娩/入院年份相匹配（1:5 的比例）。来自 RPL 和活产登记处的数据根据​​唯一的 ID 号交叉链接到以色列国家癌症登记处，并合并到一个数据库中。

结果

研究组由 937 名 RPL 患者组成，这些患者按母亲年龄 ( P  = 1.0) 和入院日期 ( P  = 0.84) 与 4685 名实现活产的妇女相匹配。组间总体癌症发病率没有差异（调整优势比 [OR] 0.76，95% 置信区间 [CI] 0.55-1.03；P  = 0.08）。与原发性 RPL 相比，继发性 RPL 组显示出癌症发病率降低的趋势（调整后的 OR 0.65，95% CI 0.41-1.03；P  = 0.07）。按癌症类型进行的分析显示，与活产相比，RPL 女性患乳腺癌的风险相似，但 RPL 女性患妇科癌症的风险显着降低（调整后的 OR 0.25，95% CI 0.08-0.79；P  = 0.018）。

结论

无法解释的 RPL 可能与较低的妇科癌症风险有关，这可能是由涉及子宫自然杀伤细胞的高反应性免疫机制解释的。