Molecular determinants of drug-specific sensitivity for epidermal growth factor receptor (EGFR) exon 19 and 20 mutants in non-small cell lung cancer

We hypothesized that aberrations activating epidermal growth factor receptor (EGFR) via dimerization would be more sensitive to anti-dimerization agents (e.g., cetuximab). EGFR exon 19 abnormalities (L747_A750del; deletes amino acids LREA) respond to reversible EGFR kinase inhibitors (TKIs). Exon 20 in-frame insertions and/or duplications (codons 767 to 774) and T790M mutations are clinically resistant to reversible/some irreversible TKIs. Their impact on protein function/therapeutic actionability are not fully elucidated.In our study, the index patient with non-small cell lung cancer (NSCLC) harbored EGFR D770_P772del_insKG (exon 20). A twenty patient trial (NSCLC cohort) (cetuximab-based regimen) included two participants with EGFR TKI-resistant mutations ((i) exon 20 D770>GY; and (ii) exon 19 LREA plus exon 20 T790M mutations). Structural modeling predicted that EGFR exon 20 anomalies (D770_P772del_insKG and D770>GY), but not T790M mutations, stabilize the active dimer configuration by increasing the interaction between the kinase domains, hence sensitizing to an agent preventing dimerization. Consistent with predictions, the two patients harboring D770_P772del_insKG and D770>GY, respectively, responded to an EGFR antibody (cetuximab)-based regimen; the T790M-bearing patient showed no response to cetuximab combined with erlotinib. In silico modeling merits investigation of its ability to optimize therapeutic selection based on structural/functional implications of different aberrations within the same gene.     

EGFR and K-Ras mutations in women with lung adenocarcinoma: implications for treatment strategy definition

Background

We aimed at investigating the outcomes of female patients with stage IIIB-IV adenocarcinoma of the lung according to EGFR and K-Ras mutational status.

Methods

One hundred and three consecutive female patients genotyped at a single Italian Institution were analyzed. Patients were planned to receive first-line platinum-based chemotherapy (CT) and a salvage treatment with anti-EGFR tyrosine-kinase inhibitors (TKIs) was proposed irrespective of tumor mutational status. EGFR (exons 18–21) and K-Ras (exon 2, codons 12–13) mutations were evaluated by real-time PCR and pyrosequencing. The association of mutational status with clinical variables and treatment benefit was investigated by chi-square test and log-rank test.

Results

EGFR and K-Ras mutations were found in 31 (30%) and 13 (15%) cases, respectively. Sixty-six patients received platinum CT: no correlation was observed between EGFR or K-Ras mutational status and response rate (RR) (p > 0.05). However, patients treated with first-line CT harboring EGFR activating mutations experienced a significantly reduced progression-free survival (PFS) in comparison with wild-type ones (4.4 vs. 6.4 months, respectively; HR 0.597, 95% CI 0.287-0.975; p = 0.048). Thirty-nine patients received salvage treatment with erlotinib: EGFR activating mutations were significantly correlated with RR (60% vs. 12.5%; p = 0.004) and PFS (11.4 vs. 4.5 months; HR 0.491, 95% CI 0.216-0.936; p = 0.044). Responses to erlotinib were not reported among women with K-Ras mutant tumors, while 50% of those with wild-type K-Ras achieved an objective remission (p = 0.296). Median PFS (3.5 vs. 8.8 months; HR 0.284, 95% CI 0.015-0.510; p = 0.010) and OS (3.9 vs. 19.8 months; HR 0.158, 95% CI 0.001-0.075; p < 0.001) were significantly shorter among K-Ras mutant patients treated with TKI.

Conclusions

In our population of Caucasian women with advanced lung adenocarcinoma we observed that the presence of EGFR activating mutations correlates with a significant reduction in the benefit from first-line platinum-based CT, emphasizing the importance of an upfront use of anti-EGFR TKIs in this patient subset. K-Ras mutations seem to correlate with a detrimental effect from anti-EGFR TKI, but this finding deserves further investigation.     

Synergistic interaction of novel lactate dehydrogenase inhibitors with gemcitabine against pancreatic cancer cells in hypoxia

Background:

Hypoxia is a driving force in pancreatic-ductal-adenocarcinoma (PDAC) growth, metastasis and chemoresistance. The muscle-isoform of lactate dehydrogenase (LDH-A) constitutes a major checkpoint for the switch to anaerobic glycolysis, ensuring supply of energy and anabolites in hypoxic-environments. Therefore, we investigated the molecular mechanisms underlying the pharmacological interaction of novel LDH-A inhibitors in combination with gemcitabine in PDAC cells.

Methods:

Lactate dehydrogenase A levels were studied by quantitative RT–PCR, western blot, immunofluorescence and activity assays in 14 PDAC cells, including primary-cell-cultures and spheroids, in normoxic and hypoxic conditions. Cell proliferation, migration and key determinants of drug activity were evaluated by sulforhodamine-B-assay, wound-healing assay, PCR and LC-MS/MS.

Results:

Lactate dehydrogenase A was significantly increased under hypoxic conditions (1% O₂), where the novel LDH-A inhibitors proved to be particularly effective (e.g., with IC₅₀ values of 0.9 vs 16.3 μM for NHI-1 in LPC006 in hypoxia vs normoxia, respectively). These compounds induced apoptosis, affected invasiveness and spheroid-growth, reducing expression of metalloproteinases and cancer-stem-like-cells markers (CD133+). Their synergistic interaction with gemcitabine, with combination index values <0.4 in hypoxia, might also be attributed to modulation of gemcitabine metabolism, overcoming the reduced synthesis of phosphorylated metabolites.

Conclusion:

Lactate dehydrogenase A is a viable target in PDAC, and novel LDH-A inhibitors display synergistic cytotoxic activity with gemcitabine, offering an innovative tool in hypoxic tumours.     

mTOR as a therapeutic target in patients with gastric cancer

The poor long-term outcomes associated with current chemotherapy treatment of patients with advanced gastric cancer suggest a need for novel targeted agents that may confer a better survival benefit. Evidence of mammalian target of rapamycin (mTOR) activation has been demonstrated in patient-derived gastric cancer cells and tumors. This review explores the relevance of the mTOR pathway to gastric cancer pathogenesis and its potential as a therapeutic target in patients with gastric cancer as well as presenting the first available clinical data on mTOR inhibitors in this disease setting. Preclinical data suggest that suppression of the mTOR pathway inhibited the proliferation of gastric cancer cells and delayed tumor progression in in vitro and animal models. In the clinical setting, the mTOR inhibitor everolimus has been active and well tolerated in phase I/II studies of patients with chemotherapy-refractory metastatic gastric cancer. Based on these promising results, everolimus currently is being investigated as a monotherapy or in combination with chemotherapeutic agents in ongoing phase II/III clinical studies.     

CDK4/6 Inhibitors Impair Recovery from Cytotoxic Chemotherapy in Pancreatic Adenocarcinoma

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肺腺癌患者血清CEA水平与EGFR-TKIs疗效相关性分析

目的 血清癌胚抗原(carcinoembrynic antigen,CEA)水平可以作为表皮生长因子受体酪氨酸激酶抑制剂(epidermal growth factor tyrosine kinase inhibitor,EGFR-TKI)疗效的预测指标,并且与表皮生长因子受体(EGFR)基因突变有关.本研究旨在探讨非小细胞肺癌(non-small cell lung cancer,NSCLC)患者血清CEA水平与EGFR-TKI治疗疗效的关系,以评估血清CEA对EGFR-TKIs治疗EGFR基因突变的肺腺癌患者预后预测价值.方法 选取山东省肿瘤医院2012-06-01-2014-09-30经手术病理确诊的69例肺腺癌患者为研究对象,通过实时定量PCR检测EGFR突变.在行EGFR-TKI治疗周期前进行血清CEA水平测定.每2个月行CT检查,以评估治疗疗效.结果 血清CEA水平＜5 ng/mL的患者有效率(PR+CR)为18.9％(5/24),疾病控制率(PR+CR+SD)为38.7％(9/24);血清CEA水平≥5 ng/mL的患者有效率为31.6％(14/45),疾病控制率为80.2％(36/45).治疗前血清CEA水平高的患者服用EGFR-TKIs药物后较血清CEA水平低的患者疗效好,差异有统计学意义,P=0.002.进一步分析两组患者的一般临床特征发现,性别、临床分期、吸烟史、年龄、PS评分均差异无统计学意义,P＞0.05.结论 高水平血清CEA(CEA水平≥25 ng/mL)肺腺癌患者的预后预测因素.     

Crizotinib and renal insufficiency: A case report and review of the literature

A 69 year old man with idiopathic chronic kidney disease was diagnosed with relapsing EGFR negative, ALK positive lung adenocarcinoma, and treated with chemotherapy and antiangiogenic treatment, under which his renal insufficiency worsened. During second line crizotinib treatment, further worsening of the renal function was seen, with very clear correlation with crizotinib withdrawal and rechallenge. No further drug causes for the worsening blood creatinine values were detected.     

伴EGFR突变肺腺癌新病理亚型接受EGFR-TKIs治疗的疗效观察

目的 肺腺癌EGFR突变不同病理亚型与表皮生长因子受体酪氨酸激酶抑制剂（EGFR-TKIs）的疗效相关性。方法 回顾性分析福州总医院2009年6月1日至2012年12月30日接受EGFR-TKIs治疗83例EGFR突变阳性晚期肺腺癌患者的病理亚型及其与EGFR-TKIs的疗效关系。病理亚型分型基于2011年肺腺癌国际多学科分类。EGFR突变检测采用PCR扩增阻滞法,疗效评估采用RECIST 1.1版标准。结果83例肺腺癌患者的疾病控制率（DCR）为77.1%,其中腺泡型为主型的DCR为82.9%,实性为主型的DCR为50%,钉凸样为主型的DCR为92.9%,其他类型（乳头样、微乳头）为主型的DCR为66.7%。83例患者的中位无病进展生存期（PFS）为16.0个月,其中腺泡型为主型的中位PFS为17.0个月,实性为主型的中位PFS为7.0个月,钉凸样为主型的中位PFS存为18.0个月,其他类型为主型（包括乳头为主型和微乳头为主型）的中位PFS为12.0个月。结论 接受EGFR-TKIs的EGFR突变肺腺癌患者中,钉突样为主型的DCR和PFS可能是最好的,而实性为主型为最差,对患者进行病理亚型分型有助于预测患者疗效。     

Impact of cigarette smoking on response to epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors in lung adenocarcinoma with activating EGFR mutations

Objectives

The aim of this study is to evaluate the predictive impact of cigarette smoking on treatment outcomes of EGFR-tyrosine kinase inhibitors (TKIs) in lung adenocarcinoma patients with activating EGFR mutations.

Methods

We retrospectively analyzed 222 consecutive recurrent or unresectable lung adenocarcinoma patients who harbored activating EGFR mutations (exon 19 deletion or exon 21 L858R) and had received gefitinib or erlotinib. Detailed smoking histories were obtained from all patients according to a standard protocol.

Results

Of 222 EGFR-mutated patients, 65.3% were never-smokers, 19.8% were smokers with <30 pack-years, and 14.9% were smokers with ≥30 pack-years smoking dosage. The disease control rate (DCR) and objective response rate (ORR) of smokers with ≥30 pack-years were significantly lower than never-smokers and smokers with <30 pack-years (DCR, 78.8% vs. 93.1%, p = 0.016; ORR, 45.5% vs. 62.4%, p = 0.020). Smokers with ≥30 pack-years showed significantly shorter PFS than never-smokers (6.4 vs. 11.8 months, p = 0.001) and smokers with <30 pack-years (6.4 vs. 11.4 months, p = 0.033), as well as shorter overall survival from the time of metastatic diagnosis than never-smokers (33.6 vs. 46.2 months, p = 0.003). There was no survival difference between smokers with <30 pack-year and never smokers. In the multivariate analysis adjusted for age, sex, performance status, initial stage, and line of EGFR-TKI, the presence of smoking dosage ≥30 pack-years was an independent predictive factor for the disease progression to EGFR-TKIs (hazard ratio, 1.87; 95% confidence interval, 1.15–3.05; p = 0.012).

Conclusions

Cigarette smoking dosage of ≥30 pack-years is an independent negative predictive factor of EGFR-TKI treatment outcome in lung adenocarcinoma patients with activating EGFR mutations.     

Pancreatic cancer: from molecular pathogenesis to targeted therapy

Pancreatic cancer is a deadly malignancy with still high mortality and poor survival despite the significant advances in understanding, diagnosis, and access to conventional and novel treatments. Though cytotoxic chemotherapy based on the purine analogue gemcitabine remains the standard approach in adjuvant and palliative setting the need for novel agents aiming at the main pathophysiological abnormalities and molecular pathways involved remains soaring. So far, evidence of clinical benefit, though small, exists only from the addition of the targeted agent erlotinib on the standard gemcitabine chemotherapy. Apart from the popular monoclonal antibodies and small molecules tyrosine kinase inhibitors, other novel compounds being tested in preclinical and clinical studies target mTOR, NF-kappaB, proteasome and histone deacetylase. These new drugs along with gene therapy and immunotherapy, which are also under clinical evaluation, may alter the unfavorable natural course of this disease. In this review we present the main pathophysiological alterations met in pancreatic cancer and the results of the florid preclinical and clinical research with regards to the targeted therapy associated to these abnormalities.     

61例肺实性型腺癌的临床特征及预后分析

探讨肺实性型腺癌的临床特征及影响预后的因素。方法：回顾性分析1975年7月至2010年4月收治的61例肺实性型腺癌患者的临床资料,其中行手术为主的综合治疗54例、非手术治疗7例。分别对性别、年龄、吸烟史、肿瘤部位、肿瘤大小、淋巴结转移、pTNM分期等因素进行预后分析。Kaplan-Meier法计算生存率,Log-rank法进行生存率显著性检验,Cox比例风险回归模型进行单因素和多因素分析,评价各因素对预后的影响。结果：全部患者的1、3和5年生存率分别为77.3%、44.8%和25.2%。单因素分析显示：肿瘤大小（P<0.001）、有无淋巴结转移（P=0.014）、M分期（P=0.013）、pTNM分期（P=0.006）、治疗方式（P<0.001）和手术方式（P=0.006）是影响预后的因素。多因素分析显示：肿瘤大小（P=0.015）、有无淋巴结转移（P<0.001）、M分期（P=0.013）和治疗方式是影响预后的独立因素。结论：肺实性型腺癌发生率低,缺乏特异性临床表征,较易发生淋巴结转移,预后差。影响其预后的因素主要为肿瘤大小、淋巴结转移、M分期和治疗方式。根治性手术是其主要治疗手段。争取早期正确诊断、选择正确的治疗方法,是提高生存率的方法。     

Presence of innate lymphoid cells in pleural effusions of primary and metastatic tumors: Functional analysis and expression of PD-1 receptor

The tumor microenvironment (TM) contains a wide variety of cell types and soluble factors capable of suppressing immune responses. While the presence of NK cells in pleural effusions (PE) has been documented, no information exists on the presence of other innate lymphoid cell (ILC) subsets and on the expression of programmed cell death-1 (PD-1) in NK and ILC. The presence of ILC was assessed in PE of 54 patients (n = 33 with mesothelioma, n = 15 with adenocarcinoma and n = 6 with inflammatory pleural diseases) by cell staining with suitable antibody combinations and cytofluorimetric analysis. The cytokine production of ILC isolated from both PE and autologous peripheral blood was analyzed upon cell stimulation and intracytoplasmic staining. We show that, in addition to NK cells, also ILC1, ILC2 and ILC3 are present in malignant PE and that the prevalent subset is ILC3. PE-ILC subsets produced their typical sets of cytokines upon activation. In addition, we analyzed the PD-1 expression on NK/ILC by multiparametric flow-cytometric analysis, while the expression of PD-1 ligand (PD-L1) was evaluated by immunohistochemical analysis. Both NK cells and ILC3 expressed functional PD-1, moreover, both tumor samples and malignant PE-derived tumor cell lines were PD-L1⁺ suggesting that the interaction between PD-1⁺ILC and PD-L1⁺tumor cells may hamper antitumor immune responses mediated by NK and ILC.     

Basis for molecular diagnostics and immunotherapy for esophageal cancer

Introduction: Esophageal cancer (EC) is an extremely aggressive neoplasm, diagnosed in about 17,000 Americans every year with a mortality rate of more than 80% within five years and a median overall survival of just 13 months. For decades, the go-to regimen for esophageal cancer patients has been the use of taxane and platinum-based chemotherapy regimens, which has yielded the field’s most dire survival statistics.

Areas covered: Combination immunotherapy and a more robust molecular diagnostic platform for esophageal tumors could improve patient management strategies and potentially extend lives beyond the current survival figures. Analyzing a panel of biomarkers including those affiliated with taxane and platinum resistance (ERCC1 and TUBB3) as well as immunotherapy effectiveness (PD-L1) would provide oncologists more information on how to optimize first-line therapy for EC.

Expert commentary: Of the 12 FDA-approved therapies in EC, zero target the genome. A majority of the approved drugs either target or are effected by proteomic expression. Therefore, a broader understanding of diagnostic biomarkers could give more clarity and direction in treating esophageal cancer in concert with a greater use of immunotherapy.     

Histogenesis of hepatoid adenocarcinoma of the stomach: molecular evidence of identical origin with coexistent tubular adenocarcinoma

Hepatoid adenocarcinoma of the stomach is a highly malignant neoplasm. Most gastric hepatoid adenocarcinomas coexist with tubular adenocarcinoma. However, the relationship between hepatoid adenocarcinoma and tubular adenocarcinoma is still unclear. In the present study, the characteristics of the coexistent tubular adenocarcinomas were determined by examining their profiles of mucin production. Subsequently, molecular pathological techniques were applied to determine the clonality of 15 mixed hepatoid and tubular adenocarcinomas of the stomach. Mucin analysis suggested that the coexistent tubular adenocarcinomas with hepatoid adenocarcinoma were of the intestinal type. The patterns of chromosome X inactivation were identical between the hepatoid adenocarcinoma component and tubular adenocarcinoma component in all of 3 informative female cases. Mutations in the p53 gene were found in 5 cases. The sequences were identical within both tumor components in all 5 cases. Microsatellite analysis indicated more than 3 common patterns of loss of heterozygosity in 8 cases. These observations strongly suggested that hepatoid adenocarcinomas were of identical origin to coexistent tubular adenocarcinomas.