基于上皮–间质转化标志物的循环肿瘤细胞表型检测对HER2阴性转移性乳腺癌一线化疗的预后意义

背景与目的上皮–间质转化(epithelia-mesenchymal,EMT)参与肿瘤细胞的转移,并且对基于上皮细胞黏附分子的循环肿瘤细胞(circulating tumor cells,CTCs)检测技术提出了挑战,CTCs已被证实是转移性乳腺癌的预后指标。虽然有证据表明基于EMT标志物的CTCs异质性与疾病进展相关,但在临床应用方面尚无统一的参考标准。本研究旨在评估基于EMT的动态CTCs检测对转移性乳腺癌患者的预后意义。方法我们从CAMELLIA III期前瞻性研究中招募了108例人表皮生长因子受体2阴性转移性乳腺癌患者,并应用CanPatrol CTC富集技术检测外周血中不同亚型的CTCs(包括上皮型CTCs、混合型上皮/间质CTCs和间质型CTCs)。应用1年无进展生存(progression-free survival,PFS)率作为界值分别寻找CTC总数和间质CTCs比例的受试者工作曲线来确定最佳阈值,并采用Kaplan-Meier分析和Cox比例风险回归分析验证综合考虑CTC总数和间质型CTCs比例制定的诊断标准的预后价值。结果CTC总数的最佳阈值为9.5[曲线下面积(area under the curve,AUC)=0.538,95%置信区间(confidence interval,CI=0.418–0.657)]及间质CTCs比例为10.7%(AUC=0.581,95%CI:0.463–0.699)作为预测1年PFS率的界值。我们采用CTC总数≥10/5 mL且间质CTCs比例>10.7%的联合标准预测PFS。符合联合标准的患者的中位PFS显著短于不符合标准的患者(6.2个月vs.9.9个月,P=0.010)。根据该标准和显著的临床病理学特征绘制列线图,C指数为0.613(P=0.010)。结论CTC总数和间质CTCs比例的联合标准可用于监测转移性乳腺癌患者的治疗耐药性和预测患者预后。

The prognostic and therapeutic implications of circulating tumor cell phenotype detection based on epithelial-mesenchymal transition markers in the first-line chemotherapy of HER2-negative metastatic breast cancer

Background:Epithelial-mesenchymal transition(EMT)is implicated in the metastatic process and presents a chal-lenge to epithelial cell adhesion molecule-based detection of circulating tumor cells(CTCs),which have been demon-strated to be a prognostic indicator in metastatic breast cancer.Although evidence has indicated that heterogeneity of CTCs based on EMT markers is associated with disease progression,no standard recommendations have been established for clinical practice.This study aimed to evaluate the prognostic significance of dynamic CTC detection based on EMT for metastatic breast cancer patients.Methods:We enrolled 108 human epidermal growth factor receptor 2-negative metastatic breast cancer patients from the prospective phase III CAMELLIA study and applied the CanPatrol CTC enrichment technique to identify CTC phenotypes(including epithelial CTCs,biphenotypic epithelial/mesenchymal CTCs,and mesenchymal CTCs)in peripheral blood samples.Receiver operating characteristic curve analyses of total CTC count and the proportion of mesenchymal CTCs for predicting the 1-year progression-free survival(PFS)rate were conducted to determine the optimal cut-off values,and Kaplan-Meier analysis and Cox proportional hazards regression analysis were performed to investigate the prognostic value of the cut-off values of both total CTC count and the proportion of mesenchymal CTCs in combination.Results:For predicting the 1-year PFS rate,the optimal cut-off value of total CTC count was 9.5(Area under the curve[AUC]=0.538,95%confidence interval[CI]=0.418-0.657),and that of the proportion of mesenchymal CTCs was 10.7%(AUC=0.581,95%CI=0.463-0.699).We used the two cut-off values in combination to forecast PFS in which the total CTC count was equaled to or exceeded 10/5 mL with the proportion of mesenchymal CTCs surpassed 10.7%.Patients who met the combined criteria had significantly shorter median PFS than did those who did not meet the criteria(6.2 vs.9.9 months,P=0.010).A nomogram was constructed based on the criteria and significant clinicopatho-logical characteristics with a C-index of 0.613(P=0.010).Conclusions: The criteria, which combine the total CTC count and the proportion of mesenchymal CTCs, may be used to monitor therapeutic resistance and predict prognosis in patients with metastatic breast cancer.