晚期非小细胞肺癌液基细胞学标本的分子检测评估和疗效评价

Assessment of liquid-based cytology based molecular analysis to guide targeted therapy in advanced non-small cell lung cancer

目的探讨液基细胞学标本基因检测在晚期非小细胞肺癌(NSCLC)分子分型及指导临床靶向治疗的应用价值。方法收集2015年3月至2017年4月中国医学科学院肿瘤医院412例晚期NSCLC患者的液基细胞学标本和临床资料,其中32例患者有手术后组织病理切片或组织活检标本,采用实时荧光定量聚合酶链反应检测表皮生长因子受体(EGFR)、鼠类肉瘤病毒癌基因(KRAS)和鼠类肉瘤过滤性毒菌致癌同源体B(BRAF)基因突变,分析基因突变与临床病理学特征的关系,对液基细胞学标本与组织学标本基因检测结果进行一致性检验。对142例使用EGFR-酪氨酸激酶抑制剂(TKI)药物治疗的患者进行临床疗效评价,生存分析采用Kaplan-Meier法。结果412例液基细胞学标本中,216例(52.4%)发生EGFR突变,36例(8.7%)发生KRAS基因突变,3例(0.7%)发生BRAF基因突变。EGFR突变与性别、病理类型、标本来源有关,其中女性患者EGFR突变率(63.0%)高于男性患者(40.8%,P<0.001),腺癌EGFR突变率(54.3%)高于非腺癌(0.0%,P<0.001)。KRAS突变与性别有关,男性突变率(12.2%)高于女性(5.6%,P=0.016)。3例多基因共突变均为Ⅳ期男性腺癌患者。32例同时有液基细胞学标本与组织学标本的患者中,30例患者的液基细胞学标本与组织学标本基因检测结果一致(Kappa=0.91)。12例组织学与液基细胞学标本均来自转移灶,基因检测结果完全一致(Kappa=1.00);19例组织学标本来自肺部原发灶、液基细胞学标本来自转移灶,18例基因检测结果一致(Kappa=0.92)。EGFR基因突变阳性患者临床应用EGFR-TKI治疗的疾病控制率(DCR)为89.0%(89/100),无进展生存时间(PFS)为13.8个月,均高于EGFR基因突变阴性患者[DCR为30.8%(4/13),中位PFS为1.4个月,均P<0.01]。结论液基细胞学标本与组织学标本的基因检测结果有高度一致性,液基细胞学标本是晚期NSCLC基因检测的重要标本来源。根据液基细胞学标本的基因检测结果进行晚期NSCLC分子分型,并指导EGFR-TKI药物靶向治疗能获得很高的DCR和PFS,具有重要临床价值。

Objective To investigate the molecular testing of liquid-based cytology(LBC)specimens from advanced non-small cell lung cancer(NSCLC)patients and the reliability of guiding targeted therapy.Methods The LBC specimens and clinical data of 412 advanced NSCLC patients from March 2015 to April 2017 in the Cancer Hospital,Chinese Academy of Medical Sciences were collected,of which 32 patients had postoperative or biopsy specimens.The real-time quantitative polymerase chain reaction was used to detect mutations of EGFR,KRAS and BRAF,and analyze the correlation between gene mutations and clinicopathological characteristics.The results of genetic testing of LBC specimens and histology specimens were examined for concordance.Clinical efficacy was evaluated in 142 patients treated with EGFR-tyrosine kinase inhibitor(TKI)drugs,and survival analysis was performed using the Kaplan-Meier method.Results Of the 412 LBC specimens,216(52.4%)had EGFR mutations,36(8.7%)had KRAS gene mutations,and 3(0.7%)had BRAF gene mutations.EGFR mutation was associated with gender,pathology type,and specimen source,with a higher EGFR mutation rate in female patients(63.0%)than in male patients(40.8%,P<0.001)and a higher EGFR mutation rate in adenocarcinoma(54.3%)than in non-adenocarcinoma(0.0%,P<0.001).KRAS mutation was related to gender,with a higher EGFR mutation rate in male patients(12.2%)than in female patients(5.6%,P=0.016).The three cases with multiple co-mutations were all stageⅣmale adenocarcinoma patients.Thirty-two patients with both LBC specimens and histology specimens had concordant genetic results between LBC specimens and histology specimens in 30 patients(Kappa=0.91).Twelve patients with both histology and LBC specimens from metastases had identical genetic results(Kappa=1.00).Nineteen patients with histology specimens from primary foci in lungs and LBC specimens from metastases had concordant genetic results between two specimens in 18 patients(Kappa=0.92).The disease control rate(DCR)for EGFR mutation-positive patients treated with EGFR-TKI was 89.0%(89/100)and the progression-free survival time(PFS)was 13.8 months,both higher than those of EGFR mutation-negative patients[DCR of 30.8%(4/13)and median PFS of 1.4 months,P<0.01].Conclusions The results of molecular testing of LBC specimens and histological specimens are highly consistent,which demonstrates LBC specimens can be a crucial source of gene testing for advanced NSCLC.Molecular typing of advanced NSCLC based on the results of genetic testing of LBC specimens and guiding EGFR-TKI drug-targeted therapy can achieve high DCR and PFS,which has important clinical value.