Sinead Noonan

Identifying the Appropriate FISH Criteria for Defining MET Copy Number–Driven Lung Adenocarcinoma through Oncogene Overlap Analysis

Introduction: Mesenchymal‐epithelial transition factor gene (MET) gene copy number gain may be a predictive biomarker for mesenchymal‐epithelial transition factor (MET) inhibition in lung cancer, but the most appropriate method and criteria for defining MET positivity are uncertain. Methods: MET copy number was assessed by fluorescence in situ hybridization in lung adenocarcinoma. Positivity criteria included mean MET per cell values greater than 5 (low [≥5 to <6], intermediate [≥6 to <7], and high [≥7]) and mean MET–to–chromosome 7 centromere ratios (MET/CEP7) of at least 1.8 (low [≥1.8 to ≤2.2], intermediate [>2.2 to <5], and high [≥5]). Associated clinical and molecular characteristics were captured. Results: Of 686 cases, 99 (14%) had a mean MET per cell value of 5 or greater, 52 of 1164 (4.5%) had a MET/CEP7 ratio of 1.8 or higher. Other oncogenic drivers (in EGFR, KRAS, anaplastic lymphoma receptor tyrosine kinase gene [ALK], erb‐b2 receptor tyrosine kinase 2 gene [ERBB2], BRAF, NRAS, ROS1, or ret proto‐oncogene [RET]) were detectable in 56% of the group with a mean MET per cell value of 5 or higher and 47% of the group with a MET/CEP7 ratio of 1.8 or higher, suggesting that many MET‐positive cases are not truly MET addicted. The rates of concomitant drivers in the groups of patients in the low, indeterminate, and high categories of mean MET per cell were 32 of 52 (62%), 12 of 19 (63%), and 11 of 27 (41%) (p = 0.2), and the rates of concomitant drivers in the low, intermediate, and high categories of MET/CEP7 ratios were 15 of 29 (52%), 9 of 18 (50%), and 0 of 4 (0%), respectively (p = 0.04). A MET/CEP7 ratio of 1.8 or higher in the absence of other oncogenes was associated with a higher rate of adrenal metastases (p = 0.03) but not with never‐smoking status. Conclusions: A fluorescence in situ hybridization MET/CEP7 ratio of 5 or higher defined a “MET‐positive” group with no oncogenic overlap. As this method and criteria are also associated with the highest response rate to MET inhibition, it represents the clearest definition of a MET copy number gain–addicted state. However, a MET‐associated phenotype may also exist across cases with a MET/CEP7 of 1.8 or higher when no other oncogene overlap occurs.

Inhibition of Dendritic Cell Maturation by the Tumor Microenvironment Correlates with the Survival of Colorectal Cancer Patients following Bevacizumab Treatment

Development of bevacizumab has improved survival in colorectal cancer, however, currently there are no biomarkers that predict response to bevacizumab and it is unknown how it influences the immune system in colorectal cancer patients. Dendritic cells are important for the induction of an antitumor immune response; however tumors are capable of disabling dendritic cells and escaping immune surveillance. The aim of this study was to assess the numbers of CD11c+ cells infiltrating tumor tissue and to examine the effects of tumor conditioned media (TCM) and bevacizumab conditioned media (BCM) on dendritic cell maturation and correlate our findings with patient survival. colorectal cancer explant tissues were cultured with or without bevacizumab, to generate BCM and TCM, which were used to treat dendritic cells. CD80, CD86, CD83, CD54, HLA-DR, and CD1d expression was measured by flow cytometry. Interleukin (IL)-10 and IL-12p70 were measured by ELISA. The Cox proportional hazards model was used to associate survival with dendritic cell inhibition. TCM and BCM inhibited lipopolysaccharide (LPS)-induced dendritic cell maturation and IL-12p70 secretion (P < 0.0001), while increasing IL-10 secretion (P = 0.0033 and 0.0220, respectively). Inhibition of LPS-induced CD1d (P = 0.021, HR = 1.096) and CD83 (P = 0.017, HR = 1.083) by TCM and inhibition of CD1d (P = 0.017, HR = 1.067), CD83 (P = 0.032, HR = 1.035), and IL-12p70 (P = 0.037, HR = 1.036) by BCM was associated with poor survival in colorectal cancer patients. CD11c expression was elevated in tumor tissue compared with normal tissue (P < 0.001), but this did not correlate with survival. In conclusion, TCM and BCM inhibit dendritic cells, and this inhibition correlates with survival of colorectal cancer patients receiving bevacizumab. Mol Cancer Ther; 11(8); 1829–37. ©2012 AACR.

Transient Asymptomatic Pulmonary Opacities Occurring during Osimertinib Treatment

Introduction: Osimertinib is an EGFR inhibitor licensed for the treatment of EGFR‐mutant, T790M‐positive NSCLC. Previously unreported, frequent transient asymptomatic pulmonary opacities were noted in patients during osimertinib therapy at the University of Colorado. Methods: Computed tomography imaging and clinical notes on patients with NSCLC who had been treated with osimertinib at the University of Colorado were retrospectively reviewed. Results: Transient asymptomatic pulmonary opacities developed in seven of 20 patients (35%) while they were receiving osimertinib. The radiological patterns seen included ground‐glass opacities with or without nodular consolidation. The median time to development of the first lesion was 8.7 weeks (range 1.6–43 weeks), the median time to resolution during continued osimertinib was 6 weeks (range 1–11 weeks). Conclusions: Transient asymptomatic pulmonary opacities may be a previously unrecognized, benign feature associated with osimertinib therapy that may be mistaken for isolated pulmonary progression or the beginning of more severe pneumonitis. If new‐onset pulmonary lesions, especially those associated with ground‐glass appearances, are asymptomatic and localized and there is no evidence of disease progression elsewhere, it may be reasonable to continue treatment with osimertinib and monitor the lesions for resolution.

Predicting response to vascular endothelial growth factor inhibitor and chemotherapy in metastatic colorectal cancer

BackgroundBevacizumab improves progression free survival (PFS) and overall survival (OS) in metastatic colorectal cancer patients however currently there are no biomarkers that predict response to this treatment. The aim of this study was to assess if differential protein expression can differentiate patients who respond to chemotherapy and bevacizumab, and to assess if select proteins correlate with patient survival.MethodsPre-treatment serum from patients with metastatic colorectal cancer (mCRC) treated with chemotherapy and bevacizumab were divided into responders and nonresponders based on their progression free survival (PFS). Serum samples underwent immunoaffinity depletion and protein expression was analysed using two-dimensional difference gel electrophoresis (2D-DIGE), followed by LC-MS/MS for protein identification. Validation on selected proteins was performed on serum and tissue samples from a larger cohort of patients using ELISA and immunohistochemistry, respectively (n = 68 and n = 95, respectively).Results68 proteins were identified following LC-MS/MS analysis to be differentially expressed between the groups. Three proteins (apolipoprotein E (APOE), angiotensinogen (AGT) and vitamin D binding protein (DBP)) were selected for validation studies. Increasing APOE expression in the stroma was associated with shorter progression free survival (PFS) (p = 0.0001) and overall survival (OS) (p = 0.01), DBP expression (stroma) was associated with shorter OS (p = 0.037). Increasing APOE expression in the epithelium was associated with a longer PFS and OS, and AGT epithelial expression was associated with a longer PFS (all p < .05). Increasing serum AGT concentration was associated with shorter OS (p = 0.009).ConclusionsAPOE, DBP and AGT identified were associated with survival outcomes in mCRC patients treated with chemotherapy and bevacizumab.

Malignant pleural disease is highly associated with subsequent peritoneal metastasis in patients with stage IV non-small cell lung cancer independent of oncogene status

INTRODUCTION Peritoneal metastasis from lung cancer is an uncommon clinical event and there are limited data on what factors predict peritoneal progression. This study retrospectively investigated whether patterns of metastatic spread and oncogene status in patients with advanced non-small cell lung cancer (NSCLC) are associated with peritoneal metastasis. METHODS Patients with metastatic non-squamous NSCLC (n=410) were identified at the University of Colorado Cancer Center. Sites of metastatic disease and baseline oncogene status (EGFR, ALK, KRAS, or triple negative) were documented via a retrospective chart review. In patients with EGFR mutations who developed peritoneal disease, we documented the presence of known resistance mechanisms. Median time to peritoneal metastasis, time from peritoneal disease to death, and overall survival were collected. RESULTS Eight percent (33/410) patients in this study developed peritoneal metastasis. Malignant pleural disease at baseline was significantly associated with subsequent peritoneal spread. There was no association between oncogene status and peritoneal metastasis. Three patients with EGFR mutations who developed peritoneal metastasis had documented resistance to tyrosine kinase inhibitors (TKIs) in the ascitic fluid. Median time from stage IV disease to peritoneal metastasis was 16.5 months (range 0.6-108 months). There were no differences in overall survival between patients who developed peritoneal metastasis and those who did not. CONCLUSIONS Malignant pleural disease is highly associated with peritoneal metastasis in patients with advanced NSCLC. The underlying mechanism is not clear. The presence of resistance mutations in ascitic fluid implies that poor drug penetration is unlikely to be the dominant mechanism. Despite being a late clinical finding, there were no differences in overall survival between patients who developed peritoneal metastasis and those who did not. Additional studies exploring treatment related factors in patients with malignant pleural disease that can reduce risk of peritoneal metastasis are warranted.

PROFILE 1014: lessons for the new era of lung cancer clinical research.

PROFILE 1014 compared crizotinib to up to six cycles of standard platinum-pemetrexed chemotherapy as the first line treatment of advanced anaplastic lymphoma kinase positive (ALK+) non-small cell lung cancer (NSCLC). Overall, PROFILE 1014 has taught us many valuable lessons about the natural history of ALK+ NSCLC, the effectiveness of key therapies and the positive ways in which clinical research in oncogene addicted subtypes of cancer continue to evolve. These lessons include (I) confirming the benefit of using personalized medicine approaches compared to chemotherapy that had already been established in EGFR mutant disease and in ALK+ disease in later lines of therapy; (II) demonstrating that molecular preselection can also affect outcomes from standard chemotherapy in addition to from targeted therapy. Specifically, the benefit of the control arm (platinum-pemetrexed), although inferior to that of crizotinib, was remarkable and expands the dataset on the increased sensitivity of ALK+ NSCLC to pemetrexed; (III) identifying the central nervous system (CNS) as a key battleground for metastatic NSCLC, especially for ALK+ disease. In PROFILE 1014 CNS time to progression (TTP) was included as a prominent secondary endpoint, which showed no difference between crizotinib and chemotherapy but all CNS lesions at baseline had to be both stable and treated, so any apparent stabilizing effect of the drug may be confounded. Ongoing studies with other ALK inhibitors vs. crizotinib that include untreated CNS diseases will provide greater clarity on the true effect of these drugs in the brain.

Baseline and On-Treatment Characteristics of Serum Tumor Markers in Stage IV Oncogene-Addicted Adenocarcinoma of the Lung

Introduction The role of serum tumor markers in the modern management of advanced NSCLC remains poorly described. Methods A single‐center retrospective analysis of available carcinoembryonic antigen, CA125, CA19.9, and CA27.29 levels at baseline and during treatment of stage IV lung adenocarcinoma by oncogenic driver was conducted. Results A total of 142 patients were analyzed (60 with anaplastic lymphoma kinase gene [ALK] rearrangement, 50 with EGFR mutation, four with ROS1 rearrangement, and 29 with KRAS mutation). Of these, 82% had at least one marker (95% if all four markers were measured), with CA27.29 being the most commonly increased and CA19.9 the rarest. Only CA27.29 differed significantly by oncogene (it was less common in KRAS) (p = 0.016). The median times to nadir during tyrosine kinase inhibitor (TKI) therapy in EGFR and ALK cases were 16.4 and 20 weeks, respectively. Of the 41 patients with EGFR mutation or ALK or ROS1 rearrangement, 24 (59%) demonstrated an initial increase within the first 4 weeks of TKI therapy, 58% of whom then had their levels fall below baseline. An increase in marker level of 10% or more from nadir occurred in 53% of systemic and 22% of central nervous system–only progression. Conclusions Serum tumor markers are frequently increased in lung adenocarcinoma regardless of driver oncogene. Changes within the first 4 weeks of therapy may be misleading. Progression is associated with marker increases, especially in sites other than the central nervous system.

KH-type splicing regulatory protein controls colorectal cancer cell growth and modulates the tumor microenvironment

Background & Aims KH-type splicing regulatory protein (KHSRP) is a multifunctional nucleic acid binding protein. KHSRP regulates transcription, mRNA decay and translation, and miRNA biogenesis. These distinct functions are associated with key aspects of cancer cell biology: inflammation and cell-fate determination. However, the role KHSRP plays in colorectal cancer (CRC) tumorigenesis remains largely unknown. Methods We investigated the oncogenic role of KHSRP in CRC using a combination of in silico analysis of large datasets, ex vivo analysis of protein expression in patient samples, and mechanistic studies using in vitro models of CRC. Results KHSRP was expressed in the epithelial and stromal compartments of both primary and metastatic tumors. Elevated KHSRP expression was found in tumor versus matched normal tissue in a cohort of 62 patients. This finding was validated in larger independent cohorts in silico. KHSRP expression was a prognostic indicator of worse overall survival (HR=3.74, 95% CI = 1.43-22.97, p=0.0138). Mechanistic data in CRC cell line models supported a role of KHSRP in driving epithelial cell proliferation in both a primary and metastatic setting, through control of the G1/S transition. Additionally, epithelial KHSRP was involved in promoting a pro-angiogenic extracellular environment, as well as regulating the secretion of oncogenic proteins involved in diverse cellular processes such as migration and response to cellular stress. Conclusion Our study has uncovered novel mechanistic-based data on the tumor-promoting effects of KHSRP in CRC. Synopsis Here we describe a pro-tumorigenic role for KHSRP in colorectal cancer. Higher KHSRP expression is associated with shorter overall survival. KHSRP regulates cancer cell proliferation and expression of proteins that govern processes including angiogenesis, migration and response to cellular stress.

Tumour vasculature immaturity, oxidative damage and systemic inflammation stratify survival of colorectal cancer patients on bevacizumab treatment

Despite treatment of patients with metastatic colorectal cancer (mCRC) with bevacizumab plus chemotherapy, response rates are modest and there are no biomarkers available that will predict response. The aim of this study was to assess if markers associated with three interconnected cancer-associated biological processes, specifically angiogenesis, inflammation and oxidative damage, could stratify the survival outcome of this cohort. Levels of angiogenesis, inflammation and oxidative damage markers were assessed in pre-bevacizumab resected tumour and serum samples of mCRC patients by dual immunofluorescence, immunohistochemistry and ELISA. This study identified that specific markers of angiogenesis, inflammation and oxidative damage stratify survival of patients on this anti-angiogenic treatment. Biomarkers of immature tumour vasculature (% IMM, p=0.026, n=80), high levels of oxidative damage in the tumour epithelium (intensity of 8-oxo-dG in nuclear and cytoplasmic compartments, p=0.042 and 0.038 respectively, n=75) and lower systemic pro-inflammatory cytokines (IL6 and IL8, p=0.053 and 0.049 respectively, n=61) significantly stratify with median overall survival (OS). In summary, screening for a panel of biomarkers for high levels of immature tumour vasculature, high levels of oxidative DNA damage and low levels of systemic pro-inflammatory cytokines may be beneficial in predicting enhanced survival outcome following bevacizumab treatment for mCRC.