Portela Sara, Cunningham Aimee, Laios Alexandros, Hutson Richard, Theophilou Georgios
Gynaecological Oncology, Leeds Teaching Hospitals NHS Trust, Leeds, GBR.
Cureus. 2021 Jan 29;13(1):e12981. doi: 10.7759/cureus.12981.
Introduction Breast cancer (BC) is a recognized risk factor for endometrial cancer (EC). Emerging literature indicates that it confers a higher risk of type II EC (T2EC) than type I EC (T1EC). Although some surgeons offer a prophylactic hysterectomy to BC patients referred for risk-reducing bilateral salpingo-oophorectomy, insufficient evidence prevents this from being the standard practice. We aimed to quantify their absolute risk and relative risk (RR) of developing both EC subtypes and identify a higher-risk group that could be considered for prophylactic hysterectomy. Methodology This retrospective service evaluation compared patients diagnosed with BC between 2008 and 2014, who subsequently developed EC within 10 years to those who did not. Absolute risk and RR were calculated using the numbers of regional BC and EC cases within this group, alongside 2009 UK female population and EC incidence statistics. Binary logistic regression generated adjusted odds ratios (ORs) for patient- and disease-specific variables. Results A total of 45 BC patients developed EC, 24 had T1EC and 21 had T2EC. Their RR of developing EC was greater than that of the general population (RR: 12.44, p < 0.0001). Notably, this was higher for T2EC (RR: 33.96, p < 0.001) than T1EC (RR: 8.63, p < 0.0001). Nonetheless, the absolute risk remained low. Tamoxifen exposure was significantly more prevalent among T2EC patients (adjusted OR: 79.61, p = 0.003). Increased age at BC diagnosis was associated with T1EC (adjusted OR: 1.10, p = 0.043) and T2EC (adjusted OR: 1.13, p = 0.03). Neither smoking status nor family history of BC was significantly associated with any outcome. Conclusion Women with BC were more likely to develop T2EC than T1EC, and although the absolute risk was low, the cumulative risk was substantial enough to warrant vigilance. Tamoxifen exposure was significantly predictive of EC, particularly T2EC, and might facilitate risk estimation. Older women at BC diagnosis who receive tamoxifen treatment should be screened and closely monitored for EC. However, given the limitations of normal screening methods for the detection of T2EC, counseling for a prophylactic hysterectomy should also be considered. Clarification of the menopausal status will help make more meaningful recommendations.
引言
乳腺癌（BC）是公认的子宫内膜癌（EC）风险因素。新出现的文献表明，与I型子宫内膜癌（T1EC）相比，其发生II型子宫内膜癌（T2EC）的风险更高。尽管一些外科医生会为因降低风险而行双侧输卵管卵巢切除术的乳腺癌患者提供预防性子宫切除术，但证据不足使其未能成为标准做法。我们旨在量化她们发生两种子宫内膜癌亚型的绝对风险和相对风险（RR），并确定可考虑进行预防性子宫切除术的高风险组。
方法
这项回顾性服务评估将2008年至2014年诊断为乳腺癌且随后在10年内发生子宫内膜癌的患者与未发生子宫内膜癌的患者进行了比较。使用该组内局部乳腺癌和子宫内膜癌病例数以及2009年英国女性人口和子宫内膜癌发病率统计数据计算绝对风险和RR。二元逻辑回归生成了针对患者和疾病特定变量的调整比值比（OR）。
结果
共有45例乳腺癌患者发生了子宫内膜癌，其中24例为T1EC，21例为T2EC。她们发生子宫内膜癌的RR高于一般人群（RR：12.44，p < 0.0001）。值得注意的是，T2EC的RR（RR：33.96，p < 0.001）高于T1EC（RR：8.63，p < 0.0001）。尽管如此，绝对风险仍然较低。他莫昔芬暴露在T2EC患者中明显更为普遍（调整OR：79.61，p = 0.003）。乳腺癌诊断时年龄增加与T1EC（调整OR：1.10，p = 0.043）和T2EC（调整OR：1.13，p = 0.03）相关。吸烟状况和乳腺癌家族史均与任何结局无显著关联。
结论
乳腺癌女性发生T2EC的可能性高于T1EC，尽管绝对风险较低，但累积风险足以引起警惕。他莫昔芬暴露是子宫内膜癌尤其是T2EC的显著预测因素，可能有助于风险评估。接受他莫昔芬治疗的乳腺癌诊断时年龄较大的女性应进行子宫内膜癌筛查并密切监测。然而，鉴于常规筛查方法在检测T2EC方面的局限性，也应考虑提供预防性子宫切除术的咨询。明确绝经状态将有助于提出更有意义的建议。
