盆腹腔上皮样炎性肌纤维母细胞肉瘤的临床病理研究

目的:为了探讨盆腹腔上皮样炎性肌纤维母细胞肉瘤的临床特点、诊断、治疗和预后,对其病理学特点进行研究分析。方法:选取2018年06月我院接诊且病理科病理诊断为盆腹腔上皮样炎性肌纤维母细胞肉瘤的1例患者作为研究对象,分别通过巨检、镜检、免疫表型以及免疫组织化学的方法对病理标本进行分析,并通过查阅相关文献,复习相关文献,对盆腹腔上皮样炎性肌纤维母细胞肉瘤的临床特点做进一步的研究。结果:镜下见肿瘤细胞排列紊乱,连成片状,大小不一,形态多样。主要组成为上皮样细胞,肿瘤细胞形状呈圆形、短梭形、多边形、椭圆形及不规则形。细胞排列较为松散,弥散分布。肿瘤细胞核仁较大,镜下可见核分裂象和瘤巨细胞;间质中见明显的大量炎症细胞浸润,炎性浸润以中性粒细胞为主,伴有少量浆细胞、淋巴细胞及嗜酸性粒细胞;胞质丰富,肿瘤细胞有明显水肿和黏液样变性。部分癌变区域排列较为密集,细胞形态不清。肿瘤细胞免疫组化结果vimentin、desmin、核膜ALK、CD30弥漫性表达强阳性,而ALK特异性的在细胞核膜阳性表达。部分肿瘤细胞EMA、INI-1、AAT、SMA、CK部分、p53部分阳性。FISH检测结果显示肿瘤细胞多有单一红色信号及红绿分离信号,多为阳性。结论:盆腹腔上皮样炎性肌纤维母细胞肉瘤发病较为罕见,是高度恶性肿瘤,预后较差。但是其病理学和免疫组化特点较为突出,根据病理学结果更有利于临床诊断。     

11例炎性肌纤维母细胞瘤的临床病理分析

  目的  研究炎性肌纤维母细胞瘤（inflammatory myofibroblastic tumor，IMT）的临床病理特点、免疫表型与诊断和预后的关系。  方法  收集2013年9月至2016年6月就诊于广西医科大学附属肿瘤医院11例IMT患者的临床病理资料，其中男性6例、女性5例，年龄13~66岁。采用免疫组织化学EnVision法等检测相关免疫标记物，分析和总结其主要的临床病理特点。  结果  11例IMT患者肿瘤发生于肺脏、纵隔、肝脏、腹腔、膀胱等部位。镜下见肿瘤由梭形纤维母细胞和肌纤维母肿瘤细胞增生构成，伴有数量不等的慢性炎细胞，个别病例见脓肿形成。间质有不同程度的黏液背景或胶原化。预后不良病例肿瘤细胞有异型性，见圆形或上皮样细胞形态及核仁。免疫组织化学染色结果显示，肿瘤细胞vimentin、ALK、SMA、S-100、CD117、CD34的阳性率依次为:91%（10/11）、55%（6/11）、100%（11/11）、27%（3/11）、18%（2/11）、9%（1/11），Ki-67阳性率为3%~40%，CK、H-caldesmon、DOG1均为阴性。随访11例患者4~22个月，7例无瘤生存，4例带瘤生存，其中3例表现出侵袭性生物学行为。  结论  IMT是一种少见的具有独特病理特征的潜在或低度恶性肿瘤，预后不良患者肿瘤细胞有异形性，可见圆形或上皮样细胞及核仁，增殖指数增高，免疫组织化学ALK，SMA，H-caldesmon可以帮助诊断。      

炎性肌纤维母细胞瘤

炎性肌纤维母细胞瘤（IMT）是近年被认识和正式命名的独立的中间型（低度恶性）肿瘤,涵盖了以往从炎性反应性病变到肿瘤的一系列诊断.发生于肺和全身各处,表现局部肿块,可伴有发热、体重减轻、盗汗及淋巴结肿大等全身症状.病变以单发或多灶发生,局部浸润性生长,侵犯血管,局部复发,少数病程进展快而致死;较大肿块局部浸润性生长临床和影像学颇似恶性肿瘤.组织学显示炎症背景下不同数量纤维母细胞、肌纤维母细胞、淋巴细胞、浆细胞、嗜酸性粒细胞和组织细胞,间质为粘液性、纤维血管性或胶原性.病变可类似炎症性反应性增生,也可出现坏死、细胞异型增生易与梭形细胞肉瘤/癌混淆.真正病因尚不清楚,已证实肿瘤内肌纤维母细胞有间变性淋巴瘤激酶（ALK）基因重排和表达,并有ALK基因与Rb-2蛋白基因的融合,证实肿瘤性增生本质.本文对该病的认识过程、遗传学研究、病理学、影像学及临床行为做一综述.     

骨的炎性肌纤维母细胞瘤并股骨头坏死1例

炎性肌纤维母细胞瘤（Inflammatory myofibroblastic tnmor，简称IMT）呈近年发现的间叶组织来源的肿瘤，该瘤可发生于几乎全身各部位，但发生于骨内的炎性肌纤维母细胞少见，我科收治1例，报道如下。     

14例肺炎性肌纤维母细胞瘤的临床病理研究

背景与目的 炎性肌纤维母细胞瘤（Inflammatory myofihroblastic tumor，IMT）是一种较为少见的好发于肺脏的真性肿瘤。本文旨在探讨肺IMT的外科临床病理特点及治疗和预后。方法 自1999年1月至2003年12月，同济医院胸心外科共收治14例肺IMT患者。切除标本均经病理组织学、免疫组织化学检查确立诊断。所有患者均接受1～5年的随访。结果 14例患者中男性8例，女性6例，年龄11～46岁。9例患者无临床症状。5例表现为咳嗽、咳血及气短等症状。IMT的诊断均通过外科切除后病理检查确立。切除肿瘤大小从1～8cm不等。病理组织学上IMT主要由梭形细胞和各种炎性细胞组成，梭形细胞在超微结构上表现为肌纤维母细胞和纤维母细胞。本组所有患者手术切除后无临床复发，随访预后良好。结论 病理组织学上。IMT是以肌纤维母细胞混以各类炎性细胞为特征，其中包括浆细胞、淋巴细胞和组织细胞。外科手术完整切除肿瘤是治疗IMT的首选方法并且预后良好。     

成人肺炎性肌纤维母细胞瘤伴淋巴结转移1例

炎性肌纤维母细胞瘤（inflammatmy myofibroblasti ctumor，IMT）是一种少见而独特的间叶性肿瘤，表现低度恶性或交界性肿瘤特点．近年WHO提出此命名，已逐渐得到广泛认同。肺IMT是由肌纤维母细胞和多种炎性细胞成分组成的肺内瘤样团块，较多见于儿童和青少年，现报道成人肺IMT伴淋巴结转移病例1例如下。     

膀胱炎性肌纤维母细胞瘤的临床病理分析

探讨膀胱炎性肌纤维母细胞瘤的临床、病理和诊治方法及预后。方法:对2例膀胱炎性肌纤维母细胞瘤患者的临床资料、病理形态学和免疫组织化学染色进行观察;对2例患者进行随访观察。结果:病例1行膀胱部分切除术,病例2行全膀胱切除+盆腔淋巴结清扫术。组织学表现均为增生的梭形或长梭形肿瘤细胞囊状分布,间质小血管增生,伴淋巴细胞、嗜酸性粒细胞及浆细胞浸润。免疫组织化学染色结果:病例1为SMA（+）,Vimentin（+）,ALK（+）。病例2为SMA（+）,CD68（+）,Vimentin（+）,Cg A（+）,ALK（-）。2例病例均不表达CK7、S-100、MyoD1、CK19、α-actin、EMA。2例患者均未见复发。结论:膀胱炎性肌纤维母细胞瘤是一种少见肿瘤,确诊主要依据组织病理学检查及免疫组织化学染色,应与横纹肌肉瘤、梭形细胞癌等鉴别,治疗以膀胱部分切除或经尿道切除为主。      

炎性肌纤维母细胞瘤

炎性肌纤维母细胞瘤又名炎性假瘤,是指由分化的肌纤维母细胞性梭形细胞组成,常伴大量炎细胞和/或淋巴细胞的一种间叶性肿瘤。炎性肌纤维母细胞瘤多发生于手术、创伤或炎症以后;临床特点：可发生于身体各个部位,发病年龄多见于儿童和青少年。显微镜下主要表现三种组织学类型：①粘液样筋膜炎样型,②富于细胞型,③少细胞纤维型;免疫组化标记常表达波形蛋白、平滑肌肌动蛋白、特异性肌动蛋白。本文结合文献对炎性肌纤维母细胞瘤作一系统的介绍,旨在促进对炎性肌纤维母细胞瘤的熟知和掌握。     

纵隔炎性肌纤维母细胞瘤1例报告并文献复习

目的：探讨纵隔炎性肌纤维母细胞瘤（inflammatorymyofibroblastictumor,IMT）的临床、病理、组织化学特性和诊断方法及预后。方法：总结1例纵隔炎性肌纤维母细胞瘤病人的临床资料,并复习国内外文献,分析和归纳炎性肌纤维母细胞瘤的临床表现、诊断和治疗。结果：患者女性,21岁,在我院全麻下行纵隔肿物切除术,术后病理示：＂左中后纵隔＂考虑炎性肌纤维母细胞瘤。术后2年,患者再次因＂出现左侧胸背部疼痛1月＂入院,在全麻下行左后纵隔占位切除术,术后病理示：恶性肌纤维母细胞瘤。术后疼痛短暂缓解,3个月后因局部疼痛,行胸部CT提示再次复发,肿瘤生长速度较前明显加快,遂给予放射治疗,纵隔肿块直线加速器适形照射DT54Gy/28fx/46d,治疗期间及治疗后3个月,复查胸部CT,提示病灶稳定,患者带瘤生存。结论：纵隔炎性肌纤维母细胞瘤依据病理学检查,应与血管源性肿瘤、神经源性肿瘤等鉴别,治疗以手术切除为主,对于手术控制不好的少数病例,可以考虑放射治疗。     

炎性肌纤维母细胞瘤诊断和治疗的研究进展

炎性肌纤维母细胞瘤是近几年逐渐被认识和命名的肿瘤,该肿瘤可发生于全身各处,表现为单发或多发肿物,伴有发热、胸痛、咳嗽咳痰、乏力、消瘦等全身症状。肿瘤局部生长,可侵犯周围血管,可复发,在影像学上形似恶性肿瘤,镜下显示不同数量的肌纤维母细胞伴炎细胞不同程度的浸润。肿瘤的病因尚不清楚,现已证实肿瘤内ALK基因重排以及表达增多。本文针对该病的认识过程、遗传学、影像学、病理学及治疗预后作一综述。     

ALK阳性非小细胞肺癌脑转移患者的治疗

背景与目的间变性淋巴瘤激酶（anaplastic lymphoma kinase, ALK）阳性非小细胞肺癌（non-small cell lung cancer, NSCLC）是肺癌的一个重要亚型。ALK阳性NSCLC脑转移患者的治疗尚无标准模式。方法本研究对我院2013年3月-2016年3月期间确诊的ALK阳性NSCLC脑转移患者的临床资料和治疗情况进行回顾性分析,探讨不同治疗模式患者的转归。结果84例晚期ALK阳性NSCLC患者中,22例初诊时有脑转移,剔除3例合并表皮生长因子受体（epidermal growth factor receptor, EGFR）双突变患者,共19例纳入分析。中位颅内疾病进展时间（progression-free survival, PFS）为12.0个月,一线脑部局部治疗（P=0.021）及一线克唑替尼治疗（P=0.030）可延长PFS;一线克唑替尼联合脑部局部治疗的中位颅内PFS为27.0个月,而单纯克唑替尼治疗的PFS仅为4.2个月。结论一线克唑替尼联合脑部局部治疗有助于延长ALK阳性晚期NSCLC患者的颅内PFS,因例数少,尚有待大样本多中心前瞻性临床研究证实。     

Correlation of extent of ALK FISH positivity and crizotinib efficacy in three prospective studies of ALK-positive patients with non-small-cell lung cancer

BackgroundIn clinical trials of patients with anaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) treated with crizotinib, evaluation of the relationship between the percentage of ALK-positive cells by fluorescence in situ hybridization (FISH)—particularly near the cut-off defining positive status—and clinical outcomes have been limited by small sample sizes.Patients and methodsData were pooled from three large prospective trials (one single-arm and two randomized versus chemotherapy) of crizotinib in patients with ALK-positive NSCLC determined by Vysis ALK Break Apart FISH using a cut-off of ≥15% ALK-positive cells. Logistic regression and proportional hazards regression analyses were used to explore the association of percent ALK-positive cells with objective response and progression-free survival (PFS), respectively.ResultsOf 11 081 screened patients, 1958 (18%) were ALK positive, 7512 (68%) were ALK negative, and 1540 (14%) were uninformative. Median percentage of ALK-positive cells was 58% in ALK-positive patients and 2% in ALK-negative patients. Of ALK-positive patients, 5% had 15%–19% ALK-positive cells; of ALK-negative patients, 2% had 10%–14% ALK-positive cells. Objective response rate for ALK-positive, crizotinib-treated patients with ≥20% ALK-positive cells was 56% (n = 700/1246), 55% (n = 725/1312) for those with ≥15% ALK-positive cells, and 38% for those with 15%–19% ALK-positive cells (n = 25/66). As a continuous variable, higher percentages of ALK-positive cells were estimated to be associated with larger differences in objective response and PFS between crizotinib and chemotherapy; however, tests for interaction between treatment and percentage of ALK-positive cells were not significant (objective response, P = 0.054; PFS, P = 0.17).ConclusionsPatients with ALK-positive NSCLC benefit from treatment with crizotinib across the full range of percentage of ALK-positive cells, supporting the clinical utility of the 15% cut-off. The small number of patients with scores near the cut-off warrant additional study given the potential for misclassification of ALK status due to technical or biologic reasons.     

The potential for crizotinib in non-small cell lung cancer: a perspective review

Tyrosine kinases have a crucial role as key regulators of signaling pathways that influence cell differentiation and growth. Dysregulation of tyrosine kinase-mediated signaling is understood to be an important oncogenic driver. Genetic rearrangements involving the tyrosine kinase anaplastic lymphoma kinase (ALK) gene occur in non-small cell lung cancer (NSCLC), anaplastic large cell lymphomoas, inflammatory myofibroblastic tumors, and other cancers. Cells with abnormal ALK signaling are sensitive to ALK inhibitors such as crizotinib. This review will highlight the discovery of the fusion between echinoderm microtubule-associated protein-like 4 (EML4) and ALK as an oncogenic driver, recognition of other ALK gene rearrangements in NSCLC, and the confirmation that crizotinib is an effective treatment for patients with ALK-positive NSCLC. Work is underway to further define the role for crizotinib in the treatment of ALK-positive lung cancer and other cancers and to investigate the molecular mechanisms for resistance to ALK inhibition with crizotinib.     

ALK基因状态与晚期肺腺癌患者一线培美曲塞化疗疗效的关系

背景与目的 间变性淋巴瘤激酶(anaplastic lymphoma kinase,ALK)是非小细胞肺癌(non-small cell lung cancer,NSCLC)的重要驱动基因之一,多项研究显示培美曲塞在ALK阳性肺癌中的疗效存在争议.本研究旨在继续探索以培美曲塞为基础的化疗在ALK阳性和阴性肺腺癌患者中的疗效.方法 回顾性分析郑州大学第一附属医院2015年1月-2016年4月经组织病理学证实的98例表皮生长因子受体(epidermal growth factor receptor,EGFR)、鼠类肉瘤病毒癌基因(kirsten rat sarcoma viral oncogene,KRAS)、鼠类肉瘤滤过性毒菌致癌同源体B1(V-rafmurine sarcoma viral oncogene homolog B1,BRAF)均为阴性的晚期肺腺癌患者的临床资料.分析ALK基因状态、临床特征、化疗疗效及无疾病进展生存期(progression-free survival,PFS)之间的关系.结果 98例患者均进行了ALK基因检测,ALK基因断裂融合34例(34.7%),未发生断裂融合64例(65.3%).全部患者均接受一线培美曲塞联合铂类的化疗,客观缓解率(objective response rate,ORR)为21.4%,疾病控制率(disease control rate,DCR)为84.7%.ALK阳性肺腺癌患者的ORR和DCR均高于阴性患者(41.2%vs 10.9%,χ2=23.389,P<0.001;91.2%vs 81.3%,χ2=4.153,P=0.042),差异有统计学意义.ALK基因状态与年龄、性别、吸烟史、临床分期均无明显关系.ALK阳性肺腺癌的中位PFS为7.1个月(95%CI:6.1-8.1),阴性4.7个月(95%CI:3.818-5.582),二者的PFS差异有统计学意义(χ2=13.269,P<0.001).Cox回归多因素分析显示:培美曲塞联合铂类化疗的PFS与性别、年龄、吸烟、分期、与铂类药物的种类均无明显关系,ALK基因断裂融合是PFS相关的唯一变量(HR=0.392,95%CI:0.243-0.634,P<0.001).结论 ALK阳性相比ALK阴性肺腺癌患者一线应用以培美曲塞为基础的化疗有更大的临床获益.     

抗肿瘤血管生成及其联合放射治疗在恶性肿瘤中的作用

 腺瘤性结肠息肉病（adenomatous polyposis coli,APC）基因是Wnt信号转导通路重要的抑癌基因,其启动子区域的异常甲基化可影响APC基因 mRNA的转录和APC蛋白的表达,导致Wnt信号传导通路异常。近年来对妇科肿瘤的多项研究中发现了APC基因启动子区域异常甲基化,并与肿瘤的发生发展有关。本文就APC基因启动子甲基化与妇科肿瘤的研究进展进行综述。     

The Biology and Clinical Features of Non–small Cell Lung Cancers with EML4-ALK Translocation

The anaplastic lymphoma kinase (ALK) acts as a dominant oncogenic driver following chromosomal rearrangements in certain cancers including non–small cell lung cancer (NSCLC). NSCLC with ALK translocation occurs in a specific subset of patients and results in unique clinical features. Crizotinib is a small molecule inhibitor of ALK kinase that has recently been approved by the FDA for the treatment of patients with ALK-positive NSCLC. Treatment with crizotinib results in clinical benefit rate of 85%–90% and a median progression-free survival of 9–10 months for this molecular subset of patients. Ongoing studies will define the impact of crizotinib on overall survival and provide insights into the resistance mechanisms and potential activation of alternate pathways. Heat shock protein 90 inhibitors also appear promising in the treatment of ALK-positive NSCLC patients, based on early results. This article reviews the characteristics, treatment, and ongoing research in patients with ALK-positive NSCLC.     

ALK inhibitors: a new targeted therapy in the treatment of advanced NSCLC

The anaplastic lymphoma kinase (ALK) fusion gene is a key oncogenic driver in a subset of patients with advanced non-small cell lung cancer (NSCLC). Oncogenic fusion genes, including echinoderm microtubule-associated protein-like 4 (EML4) and ALK, have been detected in approximately 2–7 % of NSCLC patients. Fluorescence in situ hybridization (FISH) is the recommended method for detecting ALK gene rearrangement. EML4–ALK fusion genes define a molecular subset of NSCLC with distinct clinical characteristic (lung adenocarcinoma, never or former smoker, usually mutually exclusive with EGFR mutations). Crizotinib (PF-02341066) is an orally bioavailable, ATP-competitive, small molecule inhibitor of both the receptor tyrosine kinases ALK and c-MET (hepatocyte growth factor receptor). Crizotinib has been shown to yield important clinical benefit such as objective response rate, progression-free survival (PFS), and anticipated improvements in quality of life when used in pretreated patients with advanced NSCLC harboring EML4–ALK gene rearrangement. Preliminary phase II data suggested that crizotinib is safe and well tolerated with rapid and robust antitumor activity. A phase III randomized trial in a second-line setting showed response rate and PFS (primary study endpoint) advantage for crizotinib as compared to second-line chemotherapy. Treatment-related adverse events, predominantly restricted to the gastrointestinal and visual systems, are generally self-limiting or easily managed. Crizotinib is a new standard of care for patients with advanced, ALK-positive, NSCLC. In this review, we will discuss the discovery of ALK rearrangements, the clinical epidemiology of lung cancer driven by ALK, the clinical data for ALK-targeted therapy in NSCLC, and ongoing ALK inhibitor-based clinical trials.     

Targeted therapies in non-small cell lung cancer: a focus on ALK/ROS1 tyrosine kinase inhibitors

Introduction: Anaplastic lymphoma kinase (ALK) and ROS1 rearrangements define important molecular subgroups of advanced non-small cell lung cancer (NSCLC). The identification of these genetic driver alterations created new potential for highly active therapeutic interventions. After discovery of ALK rearrangements in NSCLC, it was recognized that these confer sensitivity to ALK inhibition.

Areas covered: Crizotinib, the first-in-class ALK/ROS1/MET inhibitor, was initially approved as second-line treatment of ALK-positive advanced NSCLC but after this, it was firmly established as the standard first-line therapy for advanced ALK-positive NSCLC. After initial response to crizotinib, tumors inevitably relapse. Next-generation ALK inhibitors, more potent and brain-penetrable than crizotinib, may be effective in re-inducing remissions when cancers are still addicted to ALK. Ceritinib and alectinib are approved for metastatic ALK positive NSCLC patients, while brigatinib received granted accelerated approval by the United States Food and Drug Administration. Regarding ROS1 rearrangement, to date crizotinib is the only ALK-tyrosine kinase inhibitor receiving indication as treatment of ROS1 positive advanced NSCLC.

Expert commentary: Although novel ALK-inhibitors are under clinical investigation compared to crizotinib as front-line treatment for ALK-positive NSCLC, nowadays the current standard first-line therapy for these patients is crizotinib. Further research will clarify the best management of ALK-positive NSCLC, above all who progress on first-line crizotinib.     

Clinical characteristics and outcomes of 17 cases of inflammatory myofibroblastic tumor at a University Hospital in China

The aim of the present study was to explore the clinical and pathological characteristics, diagnosis, and treatment of inflammatory myofibroblastic tumor (IMT). A total of 17 patients with IMT diagnosed between July 2010 and February 2020 were included in the present study, and the clinical characteristics, pathological features, treatment and prognosis were analyzed retrospectively. The cohort consisted of 17 participants, including 12 men and 5 women, with a mean age of 34.76 years. The most common locations of tumors were the bronchi and the lungs (9 cases, including 1 case involving the mediastinum), followed by the colon and bladder (2 cases each), and the omentum majus, mesocolon, stomach and peritoneal cavity (1 case each). Immunohistochemical staining demonstrated that the tumor cells exhibited positive staining for anaplastic lymphoma kinase p80 (13/17), smooth muscle actin (12/17), cytokeratin pan (6/17), vimentin (5/17) and desmin (4/17). The follow-up time was 18–114 months. A patient with epithelial inflammatory myofibroblast sarcoma (EIMS) succumbed to the disease, 1 case was lost to follow-up, 2 cases relapsed and the other 13 cases were considered cured. IMTs may be malignant or low-grade. EIMS is a rare and invasive variant of IMT. The clinical and imaging manifestations are often unique and vary among individuals. Once confirmed by pathology, radical surgery should be the first choice of treatment.     

Clinical Benefit From Pemetrexed Before and After Crizotinib Exposure and From Crizotinib Before and After Pemetrexed Exposure in Patients With Anaplastic Lymphoma Kinase-Positive Non–Small-Cell Lung Cancer

BackgroundCrizotinib produces high response rates and prolonged PFS in ALK+ NSCLC. Retrospective analyses suggest enhanced sensitivity to pemetrexed in crizotinib naive ALK+ NSCLC. Cross-resistance between crizotinib and pemetrexed has not been previously investigated.Patients and MethodsPatients with stage IV ALK+ NSCLC treated with PEM-CRIZ, or CRIZ-PEM were identified. Overall PFS and PFS excluding central nervous system events (eCNS) were compared.ResultsObjective response rates in evaluable patients were 66% (PEM-CRIZ) and 75% (CRIZ-PEM) for pemetrexed and 84% (CRIZ-PEM) and 66% (PEM-CRIZ) for crizotinib. For PEM-CRIZ (n = 29), median PFS and eCNS PFS were both 6 months with pemetrexed, and 10 and 14.5 months, respectively, with crizotinib. For CRIZ-PEM (n = 9), median PFS and eCNS PFS were 4.5 and 3 months, respectively, with pemetrexed, and 8.5 and 7.5 months, respectively, with crizotinib. There was a statistically significant increase in the risk of an overall PFS event with pemetrexed when administered after crizotinib (P = .0277; hazard ratio [HR], 2.5898; 95% confidence interval [CI], 1.1100-6.0424), but differences in the risk of an eCNS PFS event were not significant (P = 0.4913; HR, 1.3521; 95% CI, 0.5727-3.1920). Neither overall nor eCNS PFS for patients while taking crizotinib was associated with a sequence effect relative to pemetrexed.ConclusionCrizotinib and pemetrexed are active drugs in ALK+ NSCLC. PFS benefit appeared higher with crizotinib than with pemetrexed. PFS benefit from pemetrexed was less after crizotinib compared with before crizotinib, however, this difference was only statistically significant for overall and not eCNS PFS. Pemetrexed exposure did not seem to affect crizotinib outcomes.