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B. Mahon



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    P1.06 - Poster Session 1 - Prognostic and Predictive Biomarkers (ID 161)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 2
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      P1.06-051 - Development of a serum biomarker panel predicting clinical outcome of chemotherapy with pemetrexed in patients with NSCLC (ID 3355)

      09:30 - 09:30  |  Author(s): B. Mahon

      • Abstract

      Background
      Pemetrexed disodium is a novel folate antimetabolite approved for first-line treatment in combination with a platinum doublet, for second-line treatment as a single agent and, more recently, as maintenance treatment after first-line chemotherapy in patients with non-squamous non-small cell lung cancer (NSCLC). Circulating factors associated with folate metabolism and/or phenotypic plasticity (e.g. the epithelial-to-mesenchymal transition (EMT)) may have predictive value in selecting advanced NSCLC for first-line pemetrexed. The objective of this study was to identify serum biomarkers capable of predicting improved outcomes for pemetrexed added to first-line platinum based chemotherapy relative to standard platinum doublet.

      Methods
      Pretreatment serum from a total of 72 patients with non-squamous stage IV NSCLC was evaluated with 76 biomarkers using Luminex immunobead assays. Patients were treated either with platinum combined with pemetrexed (P: n= 26) or with other agents (O; n=51) at the discretion of the treating physician. Patients were evaluated for disease progression using RECIST criteria. Biomarker data was processed using Ingenuity Pathway Analysis (IPA) Suite to identify interactions with folate metabolism. Cox Proportional Hazard (PH) regression model was used to assess the association between H-scores and progression-free/overall survival (PFS/OS) distribution estimated by the Kaplan-Meier method. PH interaction model was used to capture the differential effects of the biomarkers on the O vs. P treatment groups.

      Results
      Univariate PH regression analysis identified 10 biomarkers that were negatively associated (p<0.05) with progression-free survival (PFS) in either the O (sTNF-RI, sTNF-RII, Tenascin C, sIL-2Rα, spg130, sIL-6R, CA-125, and CA 19-9) or the P subgroups (total PSA, amphiregulin). Four other biomarkers (MMP-1, MMP-2, sVEGFR2, and PDGF-B) were all significantly (p<0.05) positively associated with PFS in the P group. Similarly, seven biomarkers were strongly negatively associated (p<0.01) with overall survival (OS) in the O group, including osteopontin, sTNF-RI, sTNF-RII, CA 15-3, sIL-2Rα, CYFRA 21.1, and IL-6; whereas the P group possessed both negative (osteopontin and amphiregulin) and positive (sVEGFR2, MMP-1, MMP-2, and sRAGE) associations (P<0.05) with OS. In our assessment of differential association with PFS, we found two serum biomarkers (PSA (total) and amphiregulin) with significant positive interaction terms, thus indicating differentially increased hazard of progression in the P group with higher level of the biomarker. MMP-1, HGF, and Tenascin C, sVEGFR2 were similarly noted to have significant negative interaction terms for PFS. Evaluations of the differential associations with respect to OS, demonstrated five biomarkers with significant (MMP-1, MMP-2, sVEGFR2, sTNF-RI, and Tenascin C; p≤0.05) and three strongly associated (osteopontin, HGF, s-IL-6R; p≤0.01) negative interaction terms, demonstrating a decreased hazard of progression in the P group.

      Conclusion
      Serum biomarkers with potential predictive (PFS, OS) value for selecting patients most likely to benefit from pemetrexed have been identified. Pathway analysis demonstrates interactions of biomarker candidates identified with folate metabolism. This study is currently being expanded with additional front-line patients (P=90; n=56) from our institutional archives to further evaluate their potential predictive value.

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      P1.06-052 - Biomarkers of phenotypic plasticity associated with clinical outcomes in patients with locally-advanced NSCLC treated with chemoradiation with and without surgery. (ID 3019)

      09:30 - 09:30  |  Author(s): B. Mahon

      • Abstract

      Background
      Thoracic chemoradiotherapy (CRT) with or without surgery (S) is the standard-of-care in management of stage III NSCLC. However, it appears that plateau has been reached. New treatment strategies are needed. The objective of this retrospective study was to evaluate the relationships between patient outcomes and expression of biomarkers associated with either the epithelial-to-mesenchymal transition, or EMT ( E-cadherin and vimentin), or a lung cancer “stem-cell” phenotype (CD133), DNA repair enzyme (ERCC1), and cell survival/apoptosis (BCL-2, surviving and PTEN) in attempt to identify new therapeutic strategies.

      Methods
      Stage III NSCLC pts who were treated with chest radiation (40-65Gy) and concurrently with platinum doublet and who had sufficient pretreatment tissue were included in this study. Surgical pts received 40-45 Gy of radiation preoperatively and non-surgical patients received 60-65 Gy. Immunohistochemistry was used to detect nuclear and cytoplasmic expression of ERCC1, bcl-2, survivin, PTEN, vimentin, E-cadherin, and CD133. Scores were calculated using the Allred scoring system. The log-rank tests used to evaluate progression free survival (PFS) and overall survival (OS) with Kaplan-Meier plots used to plot group characteristics.

      Results
      A total of 119 patients receiving chemoradiotherapy with adequate tumor specimens for analysis were enrolled in this study; 61 had definitive chemoradiation whereas 58 had pulmonary resection after chemoradiation. Patients (n=79) with low nuclear survivin immunostaining (score ≤6) had significantly improved PFS as compared to those patients (n=34) with higher expression levels (14.1 vs. 10.5 months, p=0.042). Patients (n=72) with a cytoplasmic vimentin score ≤ 5 had superior PFS than the with higher expression levels (n=33) (13.17 vs. 9.99 months, p=0.045). High nuclear ERCC1 values (n=72) were associated with a worse OS than those patients (n=44) with low immunostaining (22.7 vs. 59.1 months; p=0.023). Patients with low cytoplasmic E-cadherin (n=25) had a significantly better OS than those patients (n=85) with immunostaining scores (62.6 vs. 24.6 months, p=0.036). The cytoplasmic vimentin/ E-cadherin ratio provided the most impressive separation of cohort performance with high V/E ratios being associated with a poor PFS (12.6 vs. 3.1 months; score ratio 10 cutoff; p=0.00073). No significant associations with cytoplasmic CD133 were observed in this cohort for either PFS or OS.

      Conclusion
      The association of inferior overall survival in locally-advanced NSCLC patients whose tumors express high ERCC1, high cytoplasmic E-cadherin (which is associated with mesenchymal phenotype and lower adherence of cells which are able to metastasize easier), and lower progression free survival with high survivin and high vimentin/ E-cadherin ratio suggests that combining inhibitors of survivin, DNA repair, EMT pathways might improve outcomes in molecularly defined subset of stage III NSCLC patients.

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    P3.06 - Poster Session 3 - Prognostic and Predictive Biomarkers (ID 178)

    • Event: WCLC 2013
    • Type: Poster Session
    • Track: Biology
    • Presentations: 1
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      P3.06-051 - Circulating biomarkers may help guide selection of erlotinib versus chemotherapy in pretreated advanced NSCLC patients. (ID 3364)

      09:30 - 09:30  |  Author(s): B. Mahon

      • Abstract

      Background
      Recent data suggests a trend for prolonged progression-free survival (PFS) in patients with wild-type EGFR (wtEGFR) non-small cell lung cancer (NSCLC) treated with second-line docetaxel over erlotinib. In this same study, however, overall survival (OS) appeared unaffected. In the maintenance setting, erlotinib was also shown to improve both PFS and OS in wtEGFR advanced NSCLC patients. More recently, evaluating serum protein patterns by mass spectroscopy revealed inferior PFS with erlotinib compared to docetaxel in patients with a particular protein pattern. The individual proteins in the mass spectroscopy peaks were not identified. The objective of this study was to develop a multi-analyte serum panel of specific proteins with predictive value for erlotinib versus palliative chemotherapy in pretreated advanced NSCLC patients that were unselected for EGFR mutation status.

      Methods
      74 biomarkers were evaluated using Luminex immunobead assays against a total of 120 patients with stage IV NSCLC that were previously treated with chemotherapy and were unselected for EGFR mutation status. Patients were treated either with single agent erlotinib or platinum-based chemotherapy at the discretion of the treating physician. Patients were evaluated for disease progression using RECIST criteria and association of biomarker with survival outcomes was assessed using Cox proportional hazards regression model. The differential association of the biomarkers in the two treatment groups (erlotinib or chemotherapy) with survival outcomes was assessed using a proportional hazards (PH) interaction model.

      Results
      In univariate PH regression analysis, we identified 7 serum biomarkers (osteopontin, CA-125, sTNF-RII, PlGF, leptin, IGFBP5, and amphiregulin) which were strongly associated (p<0.01) and nine additional biomarkers (IGFBP4, sTNF-RI, CA 15-3, IGFBP1, sIL-2Rα, sFAS, VEGF-A, sIL-1RI, and sIL-4R) which had significant association (p<0.05) with PFS in the erlotinib subgroup (n=92). Similarly, 9 biomarkers (osteopontin, sTNF-RI, sTNF-RII, CA 15-3, sIL-2Rα, epiregulin, PILG, IL6 and CA 125) were found to be strongly associated with OS. In our assessment of differential association with PFS, we found eight serum biomarkers (sIL-2Rα, IL-8, sIL-1RI, Tensascin C, FGF2, HGF, Leptin, and TGF-α) with significant to strongly significant positive interaction terms, thus indicating differentially increased hazard of progression in the chemotherapy subgroup with high biomarker levels. Four markers (IL-8, TGF-α, HGF, VEGF-A) were found to have significantly positive interaction, indicating a decreased hazard of death in the erlotinib group with high biomarker levels; whereas two (sTNF-RII, PSA) had significant negative interaction with OS, demonstrating a increased hazard of death in the erlotinib group.

      Conclusion
      We identified a series of circulating surrogate biomarkers associated with epithelial-to-mesenchymal transition (EMT) that have promise for algorithm development to help physicians determine whether erlotinib as a single agent of chemotherapy is capable of improving outcomes in patients that progressed after first-line platinum-based chemotherapy. Current efforts focus on evaluating biomarker relationships with EGFR mutation status and algorithm validation in an effort to enhance survival in advanced stage NSCLC.