Division of Gynecologic Oncology, Department of Obstetrics and Gynecology, University of Calgary, Calgary, AB.
Department of Obstetrics and Gynecology, University of Alberta, Edmonton, AB.
J Obstet Gynaecol Can. 2020 Feb;42(2):137-143. doi: 10.1016/j.jogc.2019.06.018. Epub 2019 Nov 1.
Lynch syndrome (LS) is an autosomal dominant cancer syndrome caused by a germline mutation in the mismatch repair (MMR) genes. Protocols based on immunohistochemical expression of MMR proteins in cancer are used to identify patients with LS.
The universal LS screening protocol of the Tom Baker Cancer Centre (Calgary, AB) of all patients diagnosed between April 1, 2013 and April 1, 2015 with endometrioid carcinoma of the endometrium was audited through a retrospective chart review. LS status and frequency of protocol compliance at each of the key steps were calculated (Canadian Task Force Classification II-2).
The cohort consisted of 375 patients. MMR immunohistochemical testing was requested for 321 (85.6%). Expression of at least one protein was lost in 86 (26.8%). Twenty-one (6.5%) patients were eligible for genetic counselling because PMS2, MSH2, or MSH6 protein expression was lost in 19, and two patients had a family history of LS. Eleven (91.7%) of 12 (57.1%) who attended had germline testing, and six (54.5%) showed a mutation diagnostic of LS. LS status among the cohort of 375 patients was positive in six (1.6%), negative in 294 (78.4%), and unknown in 75 (20%) because of protocol non-compliance. LS was confirmed in six (2%) of the 321 women who completed the protocol.
This is the first audit of a Canadian-based universal LS screening protocol of patients with endometrial cancer. The success of the protocol is endorsed by the 80% compliance and by the 2% prevalence of LS, which is within the published range.
林奇综合征（LS）是一种常染色体显性遗传的癌症综合征，由错配修复（MMR）基因的种系突变引起。基于 MMR 蛋白在癌症中的免疫组织化学表达的协议用于识别 LS 患者。
通过回顾性图表审查，对 2013 年 4 月 1 日至 2015 年 4 月 1 日期间在卡尔加里汤姆贝克癌症中心（AB）诊断为子宫内膜样子宫内膜癌的所有患者的通用 LS 筛选协议进行了审核。计算了 LS 状态和每个关键步骤的协议遵守频率（加拿大工作队分类 II-2）。
该队列包括 375 名患者。321 名患者（85.6%）请求进行 MMR 免疫组织化学检测。至少一种蛋白质表达缺失 86 例（26.8%）。21 名（6.5%）患者有资格接受遗传咨询，因为 19 名患者 PMS2、MSH2 或 MSH6 蛋白表达缺失，并且两名患者有 LS 家族史。12 名（57.1%）参加的 11 名（91.7%）患者进行了种系检测，6 名（54.5%）显示出 LS 诊断的突变。375 名患者的 LS 状态为阳性 6 例（1.6%），阴性 294 例（78.4%），未知 75 例（20%），原因是协议不合规。完成协议的 321 名女性中有 6 名（2%）证实 LS。
这是对加拿大基于子宫内膜癌患者的通用 LS 筛选协议的首次审核。该协议的 80%符合率和 2%的 LS 患病率得到了认可，这在已发表的范围内。
