METHODS: A single institution cohort study of patients over 18 years with colorectal adenocarcinoma from 2018-2022 in Te Tai Tokerau, Aotearoa New Zealand was conducted. Rates of baseline immunohistochemistry (IHC) testing for mismatch repair (MMR) deficiency, further testing for MLH1-deficient cases and rates of germline mutational analysis were audited to determine adherence to national guidelines. The rate of LS in newly diagnosed CRC was estimated.
RESULTS: Six hundred and sixty patients were eligible for universal testing for LS, of which 84% (n=553) completed initial IHC testing. MMR deficiency was reported in 20% (n=114) cases. Eighty-nine percent (n=101) was attributable to MLH1 deficiency, of which 99% (n=100) were appropriately tested for BRAF-V600E mutation. Sixty-four percent (4/11) patients indicated for hypermethylation testing were appropriately tested. Seventeen patients had an indication for germline mutational analysis, of which only 29% (n=5) were tested. The estimated incidence of LS in newly diagnosed CRC was 0.7-3.8%.
CONCLUSIONS: Compliance with initial IHC testing was good. However, there is a need to improve rates of confirmation genetic testing. The incidence of confirmed LS in this study is 0.7%, however this may be as high as 3.9%.
方法:2018-2022年在TeTaiTokerau进行的18岁以上结直肠腺癌患者的单机构队列研究,新西兰进行了Aotearoa。错配修复(MMR)缺陷的基线免疫组织化学(IHC)检测率,我们对MLH1缺陷病例的进一步检测和种系突变分析率进行了审核,以确定是否遵守国家指南.估计新诊断CRC中LS的发生率。
结果:六百六十位患者有资格进行LS的通用检测,其中84%(n=553)完成了初始IHC检测。据报道,MMR缺乏的病例占20%(n=114)。89%(n=101)归因于MLH1缺乏,其中99%(n=100)进行了适当的BRAF-V600E突变检测。64%(4/11)的超甲基化测试患者进行了适当的测试。17名患者有生殖系突变分析的指征,其中只有29%(n=5)进行了测试。新诊断CRC中LS的估计发生率为0.7-3.8%。
结论:对初始IHC检测的依从性良好。然而,有必要提高基因检测的确认率。本研究中确诊LS的发生率为0.7%,然而,这可能高达3.9%。