Intratumoral heterogeneity characterized by pretreatment PET in non-small cell lung cancer patients predicts progression-free survival on EGFR tyrosine kinase inhibitor

Intratumoral heterogeneity has been suggested to be an important resistance mechanism leading to treatment failure. We hypothesized that radiologic images could be an alternative method for identification of tumor heterogeneity. We tested heterogeneity textural parameters on pretreatment FDG-PET/CT in order to assess the predictive value of target therapy. Recurred or metastatic non-small cell lung cancer (NSCLC) subjects with an activating EGFR mutation treated with either gefitinib or erlotinib were reviewed. An exploratory data set (n = 161) and a validation data set (n = 21) were evaluated, and eight parameters were selected for survival analysis. The optimal cutoff value was determined by the recursive partitioning method, and the predictive value was calculated using Harrell's C-index. Univariate analysis revealed that all eight parameters showed an increased hazard ratio (HR) for progression- free survival (PFS). The highest HR was 6.41 (P< 0.01) with co-occurrence (Co) entropy. Increased risk remained present after adjusting for initial stage, performance status (PS), and metabolic volume (MV) (aHR: 4.86, P< 0.01). Textural parameters were found to have an incremental predictive value of early EGFR tyrosine kinase inhibitor (TKI) failure compared to that of the base model of the stage and PS (C-index 0.596 vs. 0.662, P = 0.02, by Co entropy). Heterogeneity textural parameters acquired from pretreatment FDG-PET/CT are highly predictive factors for PFS of EGFR TKI in EGFR-mutated NSCLC patients. These parameters are easily applicable to the identification of a subpopulation at increased risk of early EGFR TKI failure. Correlation to genomic alteration should be determined in future studies.

Combined blockade of polo-like kinase and pan-RAF is effective against NRAS-mutant non-small cell lung cancer cells

NRAS mutation is rarely observed in non-small cell lung cancer (NSCLC) patients, and there are no approved treatments for NRAS-mutant NSCLC. Here, we evaluated the effect of pan-RAF inhibitors on human NRAS-mutant NSCLC cell lines and performed high-throughput screening using human kinome small interfering (si) RNA or CRISPR/Cas9 libraries to identify new targets for combination NSCLC treatment. Our results indicate that human NRAS-mutant NSCLC cells are moderately sensitive to pan-RAF inhibitors. High-throughput kinome screenings further showed that G2/M arrest, particularly following knockdown of polo-like kinase 1 (PLK1), can inhibit the growth of human NRAS-mutant NSCLC cells and those treated with the type II pan-RAF inhibitor LXH254. In addition, treatment with volasertib plus LXH254, resulting in dual blockade of PLK1 and pan-RAF, was found to be more effective than LXH254 monotherapy for inhibiting long-term cell viability, suggesting that this combination therapeutic strategy may lead to promising results in the clinic

Clinical Application of Next-Generation Sequencing-Based Panel to BRAF Wild-Type Advanced Melanoma Identifies Key Oncogenic Alterations and Therapeutic Strategies

Molecular profiling with next-generation sequencing (NGS) has been applied in multiple solid cancers to discover potential therapeutic targets. Here, we describe the results of a clinical NGS panel in patients with advanced melanoma. Thirty-six tumor tissues from patients with BRAF wild-type melanoma at Seoul National University Hospital (SNUH; Seoul, Republic of Korea) were collected and deep-sequenced using the SNUH FIRST-Cancer NGS panel to assess single-nucleotide variants, small insertions/deletions, copy number variations, and structural variations to estimate tumor mutation burden (TMB). We discovered 106 oncogenic alterations and most of the patients (n = 33, 92%) harbored at least one oncogenic alteration, including 2 patients who were initially diagnosed as BRAF V600E-negative but were later confirmed to be positive. Altogether, 36 samples were classified into RAS/BRAF/NF1-mutant (n = 14, 39%) or triple wild-type (n = 22, 61%) melanoma subtypes. The estimated median TMB was 8.2 mutations per Mb, ranging from 0 to 146.67 mutations per Mb. Of the 36 patients, 25 (70%) had actionable alterations with currently developed drugs, and 7 (19.4%) were enrolled in dinical trials with an RAF inhibitor, multiple receptor tyrosine kinase inhibitor, and anti-programmed cell death-1 (PD-1) antibody. TMB tended to associate with progression-free survival (PFS) of treatment with anti-PD-1/PDL-1 antibody (HR, 0.96; 95% confidence interval, 0.92-1.00; P = 0.07). High-TMB (>= 13) group was associated with longer PFS than the low-TMB group (median 34.0 vs. 11.0 weeks, P = 0.04). Overall, the dinical use of a NGS panel in patients with advanced melanoma shows association with clinical outcomes and several therapeutic strategies.

Mechanisms of Acquired Resistance to AZD9291 A Mutation-Selective, Irreversible EGFR Inhibitor

IntroductionAZD9291, a third-generation and mutation-selective epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), is active against patients with EGFRT790M-mutant non–small-cell lung cancer (NSCLC) who failed prior treatment with EGFR TKIs. However, acquired resistance to AZD9291 is inevitable. In this study, we identified the mechanisms of acquired resistance to AZD9291 in EGFRT790M-mutant NSCLC.MethodsFour NSCLC patients with both an EGFR exon 19 deletion and the EGFRT790M mutation after developing acquired resistance to first-generation EGFR TKIs received AZD9291 at doses of 20 to 80 mg/day in a phase I trial (NCT01802632). Paired tumor samples before and after treatment were obtained to evaluate EGFR modifications, alternative pathway activation, and histologic transformation. Genetic alterations were analyzed using Sanger sequencing, fluorescence in situ hybridization, real-time polymerase chain reaction, and targeted exome sequencing.ResultsAll four patients achieved a partial response (median duration of response, 9 months [range, 9–11 months]) and subsequently showed resistance to AZD9291. EGFRT790M-mutant clones depopulated AZD9291-resistant tumors to below 1% (baseline, 14%–36%) in three patients with progression: one with the loss of EGFRLREAT747del/T790M-double mutant clones and two accompanied by transformation to small-cell carcinoma and focal fibroblast growth factor receptor 1 (FGFR1) amplification, respectively. EGFRT790M-mutant clones remained and the EGFR ligand was overexpressed in one patient with focal progression to AZD9291.ConclusionAcquired resistance mechanisms of AZD9291 in patients with EGFRT790M-mutant NSCLC who failed treatment with first-generation EGFR TKIs include the loss of EGFRT790M-mutant clones plus alternative pathway activation or histologic transformation and EGFR ligand–dependent activation

Anti-tumor effects of NK cells and anti-PD-L1 antibody with antibody-dependent cellular cytotoxicity in PD-L1-positive cancer cell lines

Background Although programmed cell death-1/programmed death-ligand 1 (PD-L1) inhibitors show remarkable antitumor activity, a large portion of patients with cancer, even those with high PD-L1-expressing tumors, do not respond to their effects. Most PD-L1 inhibitors contain modified fragment crystallizable region (Fc) receptor binding sites to prevent antibody-dependent cellular cytotoxicity (ADCC) against PD-L1-expressing non-tumor cells. However, natural killer (NK) cells have specific antitumor activity in the presence of tumor-targeting antibody through ADCC, which could enhance NK cell-induced cytotoxicity. We evaluated the antitumor efficacy of ADCC via anti-PD-L1 monoclonal antibodies (mAbs) and NK cells against several PD-L1-positive cancer cell lines. Methods Various cancer cell lines were used as target cell lines. Surface PD-L1 expression was analyzed by flow cytometry. IMC-001 and anti-hPD-L1-hIgG1 were tested as anti-PD-L1 mAbs with ADCC and atezolizumab as an anti-PD-L1 mAb without ADCC. NK cell cytotoxicity was measured by(51)Cr-release assay and CD107a degranulation assay. Also, live cell imaging was performed to evaluate cytotoxicity in a single-cell level. NK-92-CD16 (CD16-transduced NK-92 cell line) and peripheral blood mononuclear cells from healthy donors, respectively, were used as an effector cell. Fc gamma RIIIa (CD16a)-V158F genotyping was performed for healthy donors. Results We demonstrated that the cytotoxicity of NK-92-CD16 cells toward PD-L1-positive cancer cell lines was significantly enhanced in the presence of anti-PD-L1 mAb with ADCC. We also noted a significant increase in primary human NK cell cytotoxicity against PD-L1-positive human cancer cells when cocultured with anti-PD-L1 mAb with ADCC. Moreover, NK cells expressing aFCGR3Ahigh-affinity genotype displayed higher anti-PD-L1 mAb-mediated ADCC lysis of tumor cells than donors with a low-affinity genotype. Conclusion These results suggest that NK cells induce an ADCC response in combination with anti-PD-L1 mAbs, which helps promote ADCC antitumor activity against PD-L1-positive tumors. This study provides support for NK cell immunotherapy against high PD-L1-expressing tumors in combination with ADCC through anti-PD-L1 mAbs.

Clinical factors affecting progression-free survival with crizotinib in ALK-positive non-small cell lung cancer

Background/Aims: Although crizotinib is standard chemotherapy for advanced anaplastic lymphoma kinase (ALK)-positive non-small cell lung cancer (NSCLC), clinical factors affecting progression-free survival (PFS) have not been reported. The purpose of this study was to identify clinical factors affecting PFS of crizotinib and develop a prognostic model for advanced ALK-positive NSCLC. Methods: Clinicopathologic features of patients enrolled in PROFILE 1001, 1005, 1007, and 1014 (training cohort) were reviewed. We conducted multivariate Cox analysis for PFS and overall survival (OS) in the training cohort (n = 159) and generated a proportional hazards model based on significant clinicopathologic factors, and then validated the model in an independent validation cohort (n = 40). Results: In the training cohort, the objective response rate was 81.5%. Median PFS and OS from the start of crizotinib were 12.4 and 31.3 months, respectively. Multivariate Cox analysis showed poor performance status, number of metastatic organs (>= 3), and no response to crizotinib independently associated shorter PFS. Based on a score derived from these three factors, median PFS and OS of patients with one or two factors were significantly shorter compared to those without these factors (median PFS, 22.4 months vs. 10.5 months vs. 6.5 months; median OS, not reached vs. 29.1 months vs. 11.8 months, respectively; p < 0.001 for each group). This model also had validated in an independent validation cohort. Conclusions: Performance status, number of metastatic organs, and response to crizotinib affected PFS of crizotinib in ALK-positive NSCLC. Based on these factors, we developed a simple and useful prediction model for PFS.

The efficacy of immune checkpoint inhibitors in anaplastic lymphoma kinase-positive non-small cell lung cancer

Background Despite recent advances in treating non-small cell lung cancer (NSCLC) with immune checkpoint inhibitors (ICIs), their role in ALK-positive NSCLC patients is unclear. We investigated the efficacy of ICIs in patients with ALK-positive NSCLC. Methods Between 2011 and 2018, a total of 14 ALK-positive NSCLC patients treated with ICIs were evaluated retrospectively. Clinicopathologic features including age, PD-L1 expression, and treatment outcomes were analyzed. RNA expression level and cytolytic activity by ALK positivity were analyzed using The Cancer Genome Atlas (TCGA) and National Cancer Center Research Institute (NCCRI) data sets. Results A total of 13 patients (92.9%) received ALK inhibitors. Patients received a median of three (range 2-8) courses of therapy. The study included nine patients (64.3%) who were PD-L1-high (>50%) and four (28.6%) who were PD-L1-low (<50%). The objective response rate was 14.3% (2/14). The median progression-free survival time was 2.18 months (95% confidence interval [CI] 1.13 months-not reached [NR]). The median overall survival time was 5.67 months (95% CI 3.00 months-NR). RNA expression levels of CD274 were similar between the ALK-positive and negative groups in both TCGA and NCCRI datasets. RNA levels of CD8A in both TCGA and NCCRI data sets were nonsignificantly lower in the ALK-positive group. Cytolytic activity scores including interferon-gamma-related response were lower in the ALK-positive group in the NCCRI but not TCGA dataset. Conclusions Despite high PD-L1-positive rates, ICIs show limited efficacy in ALK-positive NSCLC. Decreased interferon-gamma-related response may underlie these findings.

Antitumor Activity of Pembrolizumab in Biomarker-Unselected Patients With Recurrent and/or Metastatic Head and Neck Squamous Cell Carcinoma: Results From the Phase Ib KEYNOTE-012 Expansion Cohort.

Purpose Treatment with pembrolizumab, an anti-programmed death-1 antibody, at 10 mg/kg administered once every 2 weeks, displayed durable antitumor activity in programmed death-ligand 1 (PD-L1) -positive recurrent and/or metastatic (R/M) head and neck squamous cell carcinoma (HNSCC) in the KEYNOTE-012 trial. Results from the expansion cohort, in which patients with HNSCC, irrespective of biomarker status, received a fixed dose of pembrolizumab at a less frequent dosing schedule, are reported. Patients and Methods Patients with R/M HNSCC, irrespective of PD-L1 or human papillomavirus status, received pembrolizumab 200 mg intravenously once every 3 weeks. Imaging was performed every 8 weeks. Primary end points were overall response rate (ORR) per central imaging vendor (Response Evaluation Criteria in Solid Tumors v1.1) and safety. Secondary end points included progression-free survival, overall survival, and association of response and PD-L1 expression. Patients who received one or more doses of pembrolizumab were included in analyses. Results Of 132 patients enrolled, median age was 60 years (range, 25 to 84 years), 83% were male, and 57% received two or more lines of therapy for R/M disease. ORR was 18% (95% CI, 12 to 26) by central imaging vendor and 20% (95% CI, 13 to 28) by investigator review. Median duration of response was not reached (range, ≥ 2 to ≥ 11 months). Six-month progression-free survival and overall survival rates were 23% and 59%, respectively. By using tumor and immune cells, a statistically significant increase in ORR was observed for PD-L1-positive versus -negative patients (22% v 4%; P = .021). Treatment-related adverse events of any grade and grade ≥ 3 events occurred in 62% and 9% of patients, respectively. Conclusion Fixed-dose pembrolizumab 200 mg administered once every 3 weeks was well tolerated and yielded a clinically meaningful ORR with evidence of durable responses, which supports further development of this regimen in patients with advanced HNSCC

Induction chemotherapy in head and neck squamous cell carcinoma of the paranasal sinus and nasal cavity: A role in organ preservation

Background/Aims: The role of induction chemotherapy (IC) for eyeball preservation has not been established in head and neck squamous cell carcinoma (HNSCC) of the paranasal sinus and nasal cavity (PNSNC). Periorbital involvement frequently leads to eyeball exenteration with a margin of safety. We evaluated the treatment outcomes, including survival and eyeball preservation, of patients who received IC for HNSCC of the PNSNC. Methods: We reviewed 21 patients diagnosed with HNSCC of the PNSNC who were treated with IC. We analyzed response, eyeball preservation rate, and overall survival. Results: Tumors were located in the paranasal sinus (n = 14) or nasal cavity (n = 7). Most patients had stage T4a (n = 10) or T4b (n = 7) disease. More than half of the patients received a chemotherapy regimen of docetaxel, fluorouracil, and cisplatin (n = 11). Thirteen patients (61.9%) achieved a partial response after IC and 15 patients (71.4%) achieved T down-staging. Among 17 patients with stage T4 disease, which confers a high risk of orbital exenteration, 14 (82.4%) achieved preservation of the involved eye. The 3-year overall survival (OS) rate of patients who achieved a partial response to IC was 84.6%. The 3-year OS rate of patients with stable disease or disease progression after IC was 25.0% (p = 0.038). Conclusions: IC could be considered for down-staging patients with advanced T-stage disease. It could also be a reasonable option for eyeball preservation in locally advanced HNSCC of the PNSNC.

Pneumatosis Intestinalis with Pneumoperitoneum Mimicking Intestinal Perforation in a Patient with Myelodysplastic Syndrome after Hematopoietic Stem Cell Transplantation

Pneumatosis intestinalis (PI) is an uncommon disorder characterized by an accumulation of gas in the bowel wall, and has been associated with a variety of disorders and procedures. We describe a 35-year-old man who undertook hematopoietic stem cell transplantation due to myelodysplastic syndrome. An abdominal X-ray demonstrated extensive PI with pneumoperitoneum mimicking hollow organ perforation. However, the patient had no abdominal symptoms and there was no evidence of peritoneal inflammation. After two weeks of conservative management, including bowel rest and antibiotics, his pneumoperitoneum resolved spontaneously without any complications. Of the many factors that affect the gastrointestinal tract mucosal integrity, intramural pressure, and bacterial flora-produced intraluminal gas interact to produce PI. If the condition is accompanied by bowel ischemia, portomesenteric venous gas, metabolic acidosis, and abdominal sepsis, or if PI is severe in extent immediate surgical intervention is indicated. The described case supports that a mechanical rather than a bacterial etiology underlies the pathogenesis of PI