Vidula Neelima, Lipman Andrew, Kato Shumei, Weipert Caroline, Hesler Katherine, Azzi Georges, Elkhanany Ahmed, Juric Dejan, Rodriguez Estelamari, Faulkner Colleen, Makhlouf Paul, Price Kristin, O'Shaughnessy Joyce, Bardia Aditya
Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA, USA.
Florida Cancer Specialists, Sun City Center, FL, USA.
NPJ Breast Cancer. 2022 Nov 4;8(1):117. doi: 10.1038/s41523-022-00490-2.
We evaluate microsatellite instability-high (MSI-H) status with cell-free DNA (cfDNA) in metastatic breast cancer (MBC) and the association with clinico-genomic characteristics. Patients with MSI-H in cfDNA (Guardant360, 74 gene next-generation sequencing (NGS) with MBC are identified. We conduct a retrospective review. The median number of alterations and a median maximum mutant allelic fraction (MAF) in MSI-H and non-MSI-H cohorts are compared with Mann-Whitney U-test. Of 6718 patients with breast cancer with ≥1 plasma NGS alteration, 42 (0.63%) have MSI-H. A median number of genomic alterations per sample is 11 in MSI-H vs. 3 in non-MSI-H (Mann-Whitney U-test p < 0.0001) and the median maximum MAF is 16.8% in MSI-H vs. 2.6% in non-MSI-H (Mann-Whitney U-test p < 0.0001). The co-existing genomic landscape is heterogeneous. The median response duration for seven patients receiving immunotherapy is 92 days (range 29-273 days). CfDNA can identify MSI-H in MBC. Research is needed to validate immunotherapy usage in cfDNA-detected MSI-H MBC.
我们评估转移性乳腺癌（MBC）中游离DNA（cfDNA）的微卫星高度不稳定（MSI-H）状态及其与临床基因组特征的关联。通过Guardant360对MBC患者进行74基因下一代测序（NGS），以鉴定cfDNA中MSI-H的患者。我们进行了一项回顾性研究。采用Mann-Whitney U检验比较MSI-H和非MSI-H队列中的中位改变数和中位最大突变等位基因分数（MAF）。在6718例血浆NGS改变≥1的乳腺癌患者中，42例（0.63%）为MSI-H。MSI-H样本中每个样本的基因组改变中位数为11，而非MSI-H为3（Mann-Whitney U检验p<0.0001），MSI-H的中位最大MAF为16.8%，非MSI-H为2.6%（Mann-Whitney U检验p<0.0001）。共存的基因组格局是异质性的。7例接受免疫治疗患者的中位反应持续时间为92天（范围2至273天）。CfDNA可识别MBC中的MSI-H。需要开展研究以验证在cfDNA检测到的MSI-H MBC中使用免疫治疗的效果。
