云南红豆杉化学成分的研究IV：二个新紫杉烷类三环二萜成分的分离和鉴定

在继续从云南红豆杉（ＴａｓｕｓｙｕｎｎａｎｅｎｓｉｓＣｈｅｎｇｅｔＬ．Ｋ．Ｆｕ）树皮中寻找抗肿瘤活性成分的研究中，又分离出７个紫杉烷类二萜化合物，经光谱解析（ＭＳ，１ＨＮＭＲ，１Ｈ－１ＨＣＯＳＹ，１３ＣＮＭＲ，１３Ｃ－１ＨＣＯＳＹａｎｄ１３Ｃ－１ＨＣＯＬＯＣ），鉴定其中５个为已知化合物：７－ｅｐｉ－１０－ｄｅａｃｅｔｙｌｔａｘｏｌ（Ｉ），７－ｅｐｉ－１０－ｄｅａｃｅｔｙｌｃｅｐｈａｌｏｍａｎｎｉｎｅ（ＩＩ），１０－ｄｅａｃｅｔｙｌｔａｘｏｌ（ＩＩＩ），１０－ｄｅａｃｅｔｙｌｃｅｐｈａｌｏｍａｎｎｉｎｅ（ＩＶ）和１０－ｄｅａｃｅｔｙｌｂａｃｃａｔｉｎＩＩＩ（ＶＩＩ）；２个新化合物是１３（２′，３′－ｄｉｈｙｄｒｏｘｙ－３′－ｐｈｅｎｙｌ）－ｐｒｏｐｉｏｎｙｌｂａｃｃａｔｉｎ，ＩＩＩ（Ｖ）和９－ｄｅｏｘｏ－９α－ｈｙｄｒｏｘｙｔａｘｏｌ（ＶＩ），分别命名为云南红豆杉醇（ｙｕｎｎａｎｘｏｌ）和云南红豆杉胺（ｙｕｎｎａｎｘａｍｉｎｅ）。     

Detection of circulating tumour DNA after neoadjuvant chemoradiotherapy in patients with locally advanced oesophageal cancer

Active surveillance instead of standard surgery after neoadjuvant chemoradiotherapy (nCRT) has been proposed for patients with oesophageal cancer. Circulating tumour DNA (ctDNA) may be used to facilitate selection of patients for surgery. We show that detection of ctDNA after nCRT seems highly suggestive of major residual disease. Tumour biopsies and blood samples were taken before, and 6 and 12 weeks after, nCRT. Biopsies were analysed with regular targeted next-generation sequencing (NGS). Circulating cell-free DNA (cfDNA) was analysed using targeted NGS with unique molecular identifiers and digital polymerase chain reaction. cfDNA mutations matching pre-treatment biopsy mutations confirmed the presence of ctDNA. In total, 31 patients were included, of whom 24 had a biopsy mutation that was potentially detectable in cfDNA (77%). Pre-treatment ctDNA was detected in nine of 24 patients (38%), four of whom had incurable disease progression before surgery. Pre-treatment ctDNA detection had a sensitivity of 47% (95% CI 24–71) (8/17), specificity of 85% (95% CI 42–99) (6/7), positive predictive value (PPV) of 89% (95% CI 51–99) (8/9), and negative predictive value (NPV) of 40% (95% CI 17–67) (6/15) for detecting major residual disease (>10% residue in the resection specimen or progression before surgery). After nCRT, ctDNA was detected in three patients, two of whom had disease progression. Post-nCRT ctDNA detection had a sensitivity of 21% (95% CI 6–51) (3/14), specificity of 100% (95% CI 56–100) (7/7), PPV of 100% (95% CI 31–100) (3/3), and NPV of 39% (95% CI 18–64) (7/18) for detecting major residual disease. The addition of ctDNA to the current set of diagnostics did not lead to more patients being clinically identified with residual disease. These results indicate that pre-treatment and post-nCRT ctDNA detection may be useful in identifying patients at high risk of disease progression. The addition of ctDNA analysis to the current set of diagnostic modalities may not improve detection of residual disease after nCRT. © 2022 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.