循环肿瘤细胞检测在乳腺癌新辅助化疗疗效评估中的价值

Application of circulating tumor cell detection in curative effect evaluation of neoadjuvant chemotherapy for breast cancer

目的探讨乳腺癌患者外周血中循环肿瘤细胞(CTC)变化情况与乳腺癌新辅助化疗(NAC)疗效的关系。方法根据纳入、排除标准,选取第三军医大学大坪医院野战外科研究所乳腺甲状腺外科2014年12月至2016年6月收治的女性乳腺浸润性癌患者共94例进行前瞻性研究。抽取患者NAC前后健侧上肢静脉血5 ml,利用膜滤过法(ISET)检测外周血CTC。首次化疗前及2~4个周期治疗后常规行影像学检查,以实体瘤疗效评价标准(RECIST)评价疗效,无效则改行手术治疗,有效则完成6个周期化疗后行手术治疗。以病理学Miller-Payne标准作为评估疗效的金标准,根据NAC后CTC数目变化情况,将CTC降低定义为有效,CTC不变或者升高定义为无效。采用χ~2检验比较乳腺癌患者临床病理特征与CTC检出情况的关系。采用Mc Nemar检验比较NAC前后CTC阳性率的差异。治疗前后CTC数目为非正态分布,采用M(P_(25)~P_(75))表示,并用Wilcoxon符号秩和检验比较NAC前后CTC数目的差异。CTC检测与病理学金标准评估疗效的一致性分析采用Kappa检验,并采用Mc Nemar检验、敏感度和特异度评价CTC检测。结果 NAC前外周血CTC阳性率为62.8%(59/94)。与HER-2阴性及Ki67低表达患者相比,HER-2阳性[80.0%(36/45)比46.9%(23/45),χ~2=10.971,P<0.001]及Ki67高表达患者[77.4%(41/53)比44.0%(18/41),χ~2=11.072,P<0.001]中CTC阳性率更高。NAC后CTC阳性率[23.4%(22/94)比62.8%(59/94),χ~2=35.100,P<0.001]及检出数目[0(0~0)个比3(0~6)个,Z=-6.120,P<0.001]均较治疗前显著降低。CTC检测评估NAC疗效的敏感度为76.5%(39/51),特异度为69.8%(30/43);与金标准进行一致性分析,2种评价方法中等相符(Kappa=0.463,P<0.001)。结论乳腺癌患者NAC后CTC的变化情况与NAC疗效有一定关系。CTC检测有望成为一种新型评估NAC疗效的方法。

Objective To explore the relationship between circulating tumor cell （CTC） in peripheral blood of breast cancer patients and the curative effect of neoadjuvant chemotherapy for breast cancer. Methods Totally 94 breast cancer patients in Department of Breast and Thyroid Surgery, Research Institute of Surgery, Daping Hospital, Third Military Medical University, from December 2014 to June 2016 were enrolled for a prospective study according to the inclusion and exclusion criteria. Venous blood samples of 5 ml was collected from upper limb in healthy side of patients before and after neoadjuvant chemotherapy （ NAC ） , and isolation by size of epithelial tumor cells （ISET） was adopted in detecting circulating tumor cells in peripheral blood. Conventional imaging examination was given before the first chemotherapy and after 2-4 cycles of NAC to evaluate the curative effect of NAC according to Response Evaluation Criteria in Solid Tumors （ RECIST guideline version）. If the chemotherapy was ineffective, the patients shifted to surgical treatment, otherwise, the patients completed 6 cycles of NAC and then underwent surgical treatment. According to pathological evaluation standard of Miller-Payne as a gold standard for curative effect evaluation, CTC reduction was defined as effective and CTC invariant or increase was defined as ineffective by the changes of CTC number after NAC. χ2 test was used to analyze the association between the presence of CTC and clinicopathologieal characteristics of breast cancer patients. McNemar test was used to compare the positive rate of CTC before and after NAC. The number of CTC before and after treatment were expressed as M （P25- P75 ） because of its skewed distribution, and compared using Wilcoxon signed-rank test. Kappa test and McNemar test were used to evaluate the consistency between CTC detection and pathological gold standard. The sensitivity and specificity were calcuted to evaluate the CTC detection. Results The detection rate of CTC in peripheral blood before NAC was 62. 8% （59/94）. The detection rate of CTC in HER-2 positive patients was significantly higher than that in HER-2 negative patients [ 80. 0% （36/45） vs 46.9% （23/49） ,χ2 = 10. 971 ,P〈0. 001 ]. The detection rate of CTC in patients with high Ki67 expression was significantly higher than that in patients with low Ki67 expression [ 77.4% （41/53） vs 44. 0% （ 18/41 ）, χ2 = 10. 971, P〈0. 001 ]. The detection rate of CTC and the number of detected CTC after NAC were significantly lower than those before NAC [ 23.4% （22/94） vs 62. 8% （ 59/94 ）, χ2 = 35. 100, P 〈 0. 001 ; 0 （ 0-0 ） vs 3 （ 0 -6 ）, Z = - 6. 120, P 〈 0. 001 ]. The sensitivity of CTC detection in NAC efficacy evaluation was 76. 5% （39/51） and the specificity was 69. 8% （30/34）, and the consistency with the gold standard was described as moderate （Kappa = 0. 463, P〈0. 001 ）. Conclusions The alteration of CTC after NAC is related to the curative effect of NAC. CTC detection has the potential to become a new way to assess the efficacy of NAC.