Mitochondrial Aconitase ACO2 Links Iron Homeostasis with Tumorigenicity in Non-Small Cell Lung Cancer.

The ability of a patient tumor to engraft an immunodeficient mouse is the strongest known independent indicator of poor prognosis in early-stage non-small cell lung cancer (NSCLC). Analysis of primary NSCLC proteomes revealed low-level expression of mitochondrial aconitase (ACO2) in the more aggressive, engrafting tumors. Knockdown of ACO2 protein expression transformed immortalized lung epithelial cells, whereas upregulation of ACO2 in transformed NSCLC cells inhibited cell proliferation in vitro and tumor growth in vivo. High level ACO2 increased iron response element binding protein 1 (IRP1) and the intracellular labile iron pool. Impaired cellular proliferation associated with high level ACO2 was reversed by treatment of cells with an iron chelator, whereas increased cell proliferation associated with low level ACO2 was suppressed by treatment of cells with iron. Expression of CDGSH iron-sulfur (FeS) domain-containing protein 1 [CISD1; also known as mitoNEET (mNT)] was modulated by ACO2 expression level and inhibition of mNT by RNA interference or by treatment of cells with pioglitazone also increased iron and cell death. Hence, ACO2 is identified as a regulator of iron homeostasis and mNT is implicated as a target in aggressive NSCLC. IMPLICATIONS: FeS cluster-associated proteins including ACO2, mNT (encoded by CISD1), and IRP1 (encoded by ACO1) are part of an "ACO2-Iron Axis" that regulates iron homeostasis and is a determinant of a particularly aggressive subset of NSCLC.

Long-Term Efficacy and Safety of Entrectinib in ROS1 Fusion-Positive NSCLC.

Introduction: Entrectinib is an approved tyrosine kinase inhibitor (TKI) for ROS1 fusion-positive NSCLC. An updated integrated analysis of entrectinib from the ALKA-372-001, STARTRK-1, and STARTRK-2 trials is presented, with substantially longer follow-up, more patients, and the first description of the median overall survival (OS). An exploratory analysis of entrectinib in ROS1 fusion-positive NSCLC with the central nervous system (CNS)-only progression post-crizotinib is reported. Methods: Adults with ROS1 fusion-positive, locally advanced or metastatic NSCLC who received at least one dose of entrectinib and had 12 months or longer of follow-up were included in the analysis. Co-primary end points were confirmed objective response rate (ORR) and duration of response (DoR) by blinded independent central review. The data cutoff was on August 31, 2020. Results: The efficacy-assessable population comprised 168 ROS1 TKI-naïve patients. The median survival follow-up was 29.1 months (interquartile range, 21.8-35.9). The ORR was 68% (95% confidence interval [CI]: 60.2-74.8); the median DoR was 20.5 months. The median progression-free survival (PFS) was 15.7 months and the median OS was 47.8 months. In the 25 patients with measurable baseline CNS metastases, the intracranial ORR was 80% (95% CI: 59.3-93.2), median intracranial DoR was 12.9 months, and median intracranial PFS was 8.8 months. Among 18 patients with CNS-only progression on previous crizotinib treatment, two achieved a partial response (11%) and four had stable disease (22%). In seven patients with measurable CNS disease from this cohort, the intracranial ORR was 14% (1 partial response). Conclusions: Entrectinib is active and achieves prolonged survival in ROS1 TKI-naïve patients with ROS1 fusion-positive NSCLC. Modest activity is seen in patients with CNS-only progression post-crizotinib.

Updated Integrated Analysis of the Efficacy and Safety of Entrectinib in Patients With NTRK Fusion-Positive Solid Tumors.

PURPOSE: Entrectinib potently inhibits tropomyosin receptor kinases (TRKAs)/B/C and ROS1, and previously induced deep [objective response rate (ORR) 57.4%] and durable [median duration of response (DoR) 10.4 months] responses in adults with NTRK fusion-positive solid tumors from three phase I/II trials. This article expands prior reports with additional patients and longer follow-up. PATIENTS AND METHODS: Patients with locally advanced/metastatic NTRK fusion-positive solid tumors and ≥12 months' follow-up were included. Primary endpoints were ORR and DoR by blinded independent central review (BICR); secondary endpoints included progression-free survival (PFS), intracranial efficacy, and safety. The safety-evaluable populations included all patients who had received ≥1 entrectinib dose. RESULTS: At clinical cut-off (August 31, 2020), the efficacy-evaluable population comprised 121 adults with 14 tumor types and ≥30 histologies. Median follow-up was 25.8 months; 61.2% of patients had a complete (n = 19) or partial response (n = 55). Median DoR was 20.0 months [95% confidence interval (CI), 13.0-38.2]; median PFS was 13.8 months (95% CI, 10.1-19.9). In 11 patients with BICR-assessed measurable central nervous system (CNS) disease, intracranial ORR was 63.6% (95% CI, 30.8-89.1) and median intracranial DoR was 22.1 (95% CI, 7.4-not estimable) months. The safety profile of entrectinib in adults and pediatric patients was aligned with previous reports. Most treatment-related adverse events (TRAEs) were grade 1/2 and manageable/reversible with dose modifications. TRAE-related discontinuations occurred in 8.3% of patients. CONCLUSIONS: With additional clinical experience, entrectinib continues to demonstrate durable systemic and intracranial responses and can address the unmet need of a CNS-active treatment in patients with NTRK fusion-positive solid tumors.

Pan-Cancer Efficacy of Vemurafenib in BRAF V600-Mutant Non-Melanoma Cancers.

BRAF V600 mutations occur in a wide range of tumor types, and RAF inhibition has become standard in several of these cancers. Despite this progress, BRAF V600 mutations have historically been considered a clear demonstration of tumor lineage context-dependent oncogene addiction, based predominantly on the insensitivity to RAF inhibition in colorectal cancer. However, the true broader activity of RAF inhibition pan-cancer remains incompletely understood. To address this, we conducted a multicohort "basket" study of the BRAF inhibitor vemurafenib in non-melanoma BRAF V600 mutation-positive solid tumors. In total, 172 patients with 26 unique cancer types were treated, achieving an overall response rate of 33% and median duration of response of 13 months. Responses were observed in 13 unique cancer types, including historically treatment-refractory tumor types such as cholangiocarcinoma, sarcoma, glioma, neuroendocrine carcinoma, and salivary gland carcinomas. Collectively, these data demonstrate that single-agent BRAF inhibition has broader clinical activity than previously recognized. SIGNIFICANCE: These data suggest that BRAF V600 mutations lead to oncogene addiction and are clinically actionable in a broad range of non-melanoma cancers, including tumor types in which RAF inhibition is not currently considered standard of care.See related commentary by Ribas and Lo, p. 640.This article is highlighted in the In This Issue feature, p. 627.

Efficacy of Vemurafenib in Patients With Non-Small-Cell Lung Cancer With BRAF V600 Mutation: An Open-Label, Single-Arm Cohort of the Histology-Independent VE-BASKET Study.

PURPOSE: To study whether BRAF V600 mutations in non-small-cell lung cancer (NSCLC) may indicate sensitivity to the BRAF inhibitor vemurafenib, we included a cohort of patients with NSCLC in the vemurafenib basket (VE-BASKET) study. On the basis of observed early clinical activity, we expanded the cohort of patients with NSCLC. We present results from this cohort. METHODS: This open-label, histology-independent, phase II study included six prespecified cohorts, including patients with NSCLC, and a seventh all-comers cohort. Patients received vemurafenib (960 mg two times per day) until disease progression or unacceptable toxicity. The primary end point of the final analysis was objective response rate (Response Evaluation Criteria in Solid Tumors, version 1.1). Secondary end points included progression-free survival, overall survival, and safety. Because the prespecified clinical benefit endpoint was met in the initial NSCLC cohort, the cohort was expanded. RESULTS: Sixty-two patients with BRAF V600-mutant NSCLC were enrolled and treated: 13% (n = 8) had received no prior systemic therapy, and 87% (n = 54) had received prior therapies. The objective response rate was 37.1% (95% CI, 25.2% to 50.3%) overall, 37.5% (95% CI, 8.5% to 75.5%) in previously untreated patients, and 37.0% (24.3% to 51.3%) in previously treated patients. Median progression-free survival was 6.5 months (95% CI, 5.2 to 9.0 months), and median overall survival was 15.4 months (95% CI, 9.6 to 22.8 months). The most common all-grade adverse event was nausea (40%). The safety profile of vemurafenib was similar to that observed in melanoma studies. CONCLUSION: Vemurafenib showed promising activity in patients with NSCLC harboring BRAF V600 mutations. The safety profile of vemurafenib was similar to previous observations in patients with melanoma. Our results suggest a role for single-agent BRAF inhibition in patients with NSCLC and BRAF V600 mutations.

BRAF Inhibition in BRAFV600-Mutant Gliomas: Results From the VE-BASKET Study.

PURPOSE: BRAFV600 mutations are frequently found in several glioma subtypes, including pleomorphic xanthoastrocytoma (PXA) and ganglioglioma and much less commonly in glioblastoma. We sought to determine the activity of vemurafenib, a selective inhibitor of BRAFV600, in patients with gliomas that harbor this mutation. PATIENTS AND METHODS: The VE-BASKET study was an open-label, nonrandomized, multicohort study for BRAFV600-mutant nonmelanoma cancers. Patients with BRAFV600-mutant glioma received vemurafenib 960 mg twice per day continuously until disease progression, withdrawal, or intolerable adverse effects. Key end points included confirmed objective response rate by RECIST version 1.1, progression-free survival, overall survival, and safety. RESULTS: Twenty-four patients (median age, 32 years; 18 female and six male patients) with glioma, including malignant diffuse glioma (n = 11; six glioblastoma and five anaplastic astrocytoma), PXA (n = 7), anaplastic ganglioglioma (n = 3), pilocytic astrocytoma (n = 2), and high-grade glioma, not otherwise specified (n = 1), were treated. Confirmed objective response rate was 25% (95% CI, 10% to 47%) and median progression-free survival was 5.5 months (95% CI, 3.7 to 9.6 months). In malignant diffuse glioma, best response included one partial response and five patients with stable disease, two of whom had disease stabilization that lasted more than 1 year. In PXA, best response included one complete response, two partial responses, and three patients with stable disease. Additional partial responses were observed in patients with pilocytic astrocytoma and anaplastic ganglioglioma (one each). The safety profile of vemurafenib was generally consistent with that of previously published studies. CONCLUSION: Vemurafenib demonstrated evidence of durable antitumor activity in some patients with BRAFV600-mutant gliomas, although efficacy seemed to vary qualitatively by histologic subtype. Additional study is needed to determine the optimal use of vemurafenib in patients with primary brain tumors and to identify the mechanisms driving differential responses across histologic subsets.

Vemurafenib for BRAF V600-Mutant Erdheim-Chester Disease and Langerhans Cell Histiocytosis: Analysis of Data From the Histology-Independent, Phase 2, Open-label VE-BASKET Study.

IMPORTANCE: The histiocytic neoplasms Erdheim-Chester disease (ECD) and Langerhans cell histiocytosis (LCH) are highly enriched for BRAF V600 mutations and have been previously shown to be responsive to treatment with vemurafenib, an inhibitor of the BRAF V600 kinase. However, the long-term efficacy and safety of prolonged vemurafenib use in these patients are not defined. Here we analyze the final efficacy and safety data for vemurafenib in patients with ECD and LCH enrolled in the VE-BASKET study. OBJECTIVE: To determine the efficacy and safety of vemurafenib in adults with ECD or LCH enrolled in the VE-BASKET study. DESIGN, SETTING, AND PARTICIPANTS: The VE-BASKET study was an open-label, nonrandomized, multicohort study for patients with nonmelanoma cancers harboring the BRAF V600 mutation. Patients with BRAF V600-mutant ECD or LCH were enrolled in an "other solid tumor" cohort of the VE-BASKET study, and they were enrolled in the present study. INTERVENTIONS: Patients received vemurafenib, 960 mg, twice daily continuously until disease progression, study withdrawal, or occurrence of intolerable adverse effects. MAIN OUTCOMES AND MEASURES: The primary end point was confirmed objective response rate (ORR) by Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1). Secondary end points included progression-free survival (PFS), overall survival (OS), metabolic response by modified positron-emission tomography (PET) Response Criteria in Solid Tumors (PERCIST) using 18F-fluorodeoxyglucose (FDG)-PET/computed tomography (CT), and safety. RESULTS: A total of 26 patients from the VE-BASKET trial (22 with ECD, 4 with LCH) were included in the present study (14 women and 12 men; median age, 61 years; age range, 51-74 years). The confirmed ORR was 61.5% (95% CI, 40.6%-79.8%) in the overall cohort and 54.5% (95% CI, 32.2%-75.6%) in patients with ECD. All evaluable patients achieved stable disease or better. The median PFS and OS had not been reached in the overall cohort at study closure despite a median follow-up of 28.8 months; 2-year PFS was 86% (95% CI, 72%-100%), and 2-year OS was 96% (95% CI, 87%-100%). All 15 patients evaluated by FDG-PET/CT achieved a metabolic response, including 12 patients (80%) with a complete metabolic response. The most common adverse events (AEs) in the overall cohort included arthralgia, maculopapular rash, fatigue, alopecia, prolonged QT interval, skin papilloma, and hyperkeratosis. Hypertension and dermatologic AEs occurred at higher rates than those reported in metastatic melanoma. CONCLUSIONS AND RELEVANCE: In this study, vemurafenib had prolonged efficacy in patients with BRAF V600-mutant ECD and LCH and warrants consideration as a new standard of care for these patients.

Prognostic and predictive effects of TP53 co-mutation in patients with EGFR-mutated non-small cell lung cancer (NSCLC).

INTRODUCTION: TP53 mutations are common in non-small cell lung cancer (NSCLC) and have been reported as prognostic of poor outcome. The impact of TP53 co-mutations in epidermal growth factor receptor (EGFR)-mutated NSCLC is unclear. MATERIALS AND METHODS: Tissue from 105 patients with EGFR-mutated NSCLC at Princess Margaret Cancer Centre was analyzed by next-generation or Sanger sequencing to determine TP53 mutational status. Associations between TP53 status and baseline patient and tumor characteristics, treatments and outcomes (relapse-free survival [RFS] after surgical resection, overall survival [OS], overall response rate [ORR] and progression-free survival [PFS] on EGFR tyrosine kinase inhibitors [TKIs]), were investigated. RESULTS: Dual TP53/EGFR mutations were found in 43/105 patients (41%). Among 76 patients who underwent surgical resection, neither RFS (HR 0.99, CI 0.56-1.75, p=0.96) nor OS (HR 1.39, CI 0.70-2.77; p=0.35) was associated with TP53 status. Sixty patients (24 TP53 MUT; 36 TP53 WT) received first-generation EGFR TKIs for advanced disease. ORR was not significantly different (TP53 MUT 54%, WT 66%, p=0.42). There was a non-significant trend towards shorter PFS on EGFR TKIs with TP53 mutation (HR 1.74, CI 0.98-3.10, p=0.06). When limited to TP53 missense mutations (n=17), PFS was significantly shorter (HR 1.91, CI 1.01-3.60, p=0.04). Among 11 evaluable patients treated with T790M inhibitors, ORR was not significantly different (TP53 MUT 3/3 [100%], WT 7/8 [88%]). CONCLUSIONS: Patients with dual TP53/EGFR mutations, especially missense mutations, had marginally lower response rates and shorter PFS when treated with EGFR TKI therapy. Larger datasets are required to validate these observations.

Hazards and incidents: Detection and learning in radiation medicine, a comparison of 2 educational interventions.

PURPOSE: Interprofessional, educational live simulations were compared with group discussion-based exercises in terms of their ability to improve radiation medicine trainees' ability to detect hazards and incidents and understand behaviors that may prevent them. METHODS AND MATERIALS: Trainees and recent graduates of radiation therapy, medical physics, and radiation oncology programs were recruited and randomized to either a simulation-based or group discussion-based training intervention. Participants engaged in hazard and incident detection, analysis, and a discussion of potential preventive measures and the concept of the "highly reliable team." A video examination tool modeled on actual incidents, using 5-minute videos created by faculty, students, and volunteers, was created to test hazard and incident recognition ability before and after training. Hazard and incident detection sensitivity and specificity analyses were conducted, and a survey of the participants' and facilitators' perceptions was conducted. RESULTS: Twenty-seven participants were assigned to the simulation (n = 15) or discussion group (n = 12). Hazard and incident-detection sensitivity ranged from 0.04 to 0.56 before and 0.04 to 0.35 after training for the discussion and simulation groups, respectively. The pre- and posttraining difference in sensitivity between groups was 0.03 (P = .75) for the minimum and 0.33 (P = .034) for the maximum reaction time. Participant perceptions of the training's educational value in a variety of domains ranged from a mean score of 6.58 to 8.17 and 7 to 8.07 for the discussion and simulation groups, respectively. Differences were not statistically significant. Twenty-six of the 27 participants indicated that they would recommend this event to a colleague. CONCLUSIONS: Participants' ability to detect hazards and incidents as portrayed in 5-minute videos in this study was low both before and after training, and simulation-based training was not superior to discussion-based training. However, levels of satisfaction and perceptions of the training's educational value were high, especially with simulation-based training.

Improved detection of clinically relevant wound bacteria using autofluorescence image-guided sampling in diabetic foot ulcers.

Clinical wound assessment involves microbiological swabbing of wounds to identify and quantify bacterial species, and to determine microbial susceptibility to antibiotics. The Levine swabbing technique may be suboptimal because it samples only the wound bed, missing other diagnostically relevant areas of the wound, which may contain clinically significant bacteria. Thus, there is a clinical need to improve the reliability of microbiological wound sampling. To address this, a handheld portable autofluorescence (AF) imaging device that detects bacteria in real time, without contrast agents, was developed. Here, we report the results of a clinical study evaluating the use of real-time AF imaging to visualise bacteria in and around the wound bed and to guide swabbing during the clinical assessment of diabetic foot ulcers, compared with the Levine technique. We investigated 33 diabetic foot ulcers (n = 31 patients) and found that AF imaging more accurately identified the presence of moderate and/or heavy bacterial load compared with the Levine technique (accuracy 78% versus 52%, P = 0·048; adjusted diagnostic odds ratio 7·67, P < 0·00022 versus 3·07, P = 0·066) and maximised the effectiveness of bacterial load sampling, with no significant impact on clinical workflow. AF imaging may help clinicians better identify the wound areas with clinically significant bacteria, and maximise sampling of treatment-relevant pathogens.

Assessment of a prognostic model, PSA metrics and toxicities in metastatic castrate resistant prostate cancer using data from Project Data Sphere (PDS).

BACKGROUND: Prognostic models in metastatic castrate resistant prostate cancer (mCRPC) may have clinical utility. Using data from PDS, we aimed to 1) validate a contemporary prognostic model (Templeton et al., 2014) 2) evaluate prognostic impact of concomitant medications and PSA decrease 3) evaluate factors associated with docetaxel toxicity. METHODS: We accessed data on 2,449 mCRPC patients in PDS. The existing model was validated with a continuous risk score, time-dependent receiver operating characteristic (ROC) curves, and corresponding time-dependent Area under the Curve (tAUC). The prognostic effects of concomitant medications and PSA response were assessed by Cox proportional hazards models. One year tAUC was calculated for multivariable prognostic model optimized to our data. Conditional logistic regression models were used to assess associations with grade 3/4 adverse events (G3/4 AE) at baseline and after cycle 1 of treatment. RESULTS: Despite limitations of the PDS data set, the existing model was validated; one year AUC, was 0.68 (95% CI 95% CI, .66 to .71) to 0.78 (95%CI, .74 to .81) depending on the subset of datasets used. A new model was constructed with an AUC of .74 (.72 to .77). Concomitant medications low molecular weight heparin and warfarin were associated with poorer survival, Metformin and Cox2 inhibitors were associated with better outcome. PSA response was associated with survival, the effect of which was greatest early in follow-up. Age was associated with baseline risk of G3/4 AE. The odds of experiencing G3/4 AE later on in treatment were significantly greater for subjects who experienced a G3/4 AE in their first cycle (OR 3.53, 95% CI 2.53-4.91, p < .0001). CONCLUSION: Despite heterogeneous data collection protocols, PDS provides access to large datasets for novel outcomes analysis. In this paper, we demonstrate its utility for validating existing models and novel model generation including the utility of concomitant medications in outcome analyses, as well as the effect of PSA response on survival and toxicity prediction.

Patient-Derived Xenograft Establishment from Human Malignant Pleural Mesothelioma.

Purpose: Malignant pleural mesothelioma (MPM) is a rare but aggressive disease with few therapeutic options. The tumor-stromal interface is important in MPM, but this is lost in cell lines, the main model used for preclinical studies. We sought to characterize MPM patient-derived xenografts (PDX) to determine their suitability as preclinical models and whether tumors that engraft reflect a more aggressive biological phenotype.Experimental Design: Fresh tumors were harvested from extrapleural pneumonectomy, decortication, or biopsy samples of 50 MPM patients and implanted subcutaneously into immunodeficient mice and serially passaged for up to five generations. We correlated selected mesothelioma biomarkers between PDX and patient tumors, and PDX establishment with the clinical pathologic features of the patients, including their survival. DNA of nine PDXs was profiled using the OncoScan FFPE Express platform. Ten PDXs were treated with cisplatin and pemetrexed.Results: A PDX was formed in 20 of 50 (40%) tumors implanted. Histologically, PDX models closely resembled the parent tumor. PDX models formed despite preoperative chemotherapy and radiotherapy. In multivariable analysis, patients whose tumors formed a PDX had significantly poorer survival when the model was adjusted for preoperative treatment (HR, 2.46; 95% confidence interval, 1.1-5.52; P = 0.028). Among 10 models treated with cisplatin, seven demonstrated growth inhibition. Genomic abnormalities seen in nine PDX models were similar to that previously reported.Conclusions: Patients whose tumors form PDX models have poorer clinical outcomes. MPM PDX tumors closely resemble the genotype and phenotype of parent tumors, making them valuable models for preclinical studies. Clin Cancer Res; 23(4); 1060-7. ©2016 AACR.

Predictive value of molecular remissions postconsolidation chemotherapy in patients with Core Binding Factor Acute Myeloid Leukemia (CBF-AML) - a single center analysis.

We analyzed the outcome of 80 sequential patients with core binding factor acute myeloid leukemia and evaluated the influence of molecular monitoring by quantitative reverse transcriptase polymerase chain reaction. With a median follow-up of 5 years, the estimated 5-year relapse-free survival and overall survival were 58% and 66%, respectively. Patients who were in molecular remission at the completion of consolidation chemotherapy had a 21% risk of relapse, while the relapse risk for those in molecular remission at the end of 2 years was 5.5%. Our data indicate that postconsolidation molecular remission does not necessarily preclude disease relapse and further monitoring is required. In contrast, molecular negativity by quantitative reverse transcriptase polymerase chain reaction at the end of 2 years is associated with a low risk of relapse.

MATE2 Expression Is Associated with Cancer Cell Response to Metformin.

BACKGROUND: There is great interest in repurposing the commonly prescribed anti-diabetic drug metformin for cancer therapy. Intracellular uptake and retention of metformin is affected by the expression of organic cation transporters (OCT) 1-3 and by multidrug and toxic compound extrusion (MATE) 1-2. Inside cells, metformin inhibits mitochondrial function, which leads to reduced oxygen consumption and inhibition of proliferation. Reduced oxygen consumption can lead to improved tumor oxygenation and radiation response. PURPOSE: Here we sought to determine if there is an association between the effects of metformin on inhibiting oxygen consumption, proliferation and expression of OCTs and MATEs in a panel of 19 cancer cell lines. RESULTS: There was relatively large variability in the anti-proliferative response of different cell lines to metformin, with a subset of cell lines being very resistant. In contrast, all cell lines demonstrated sensitivity to the inhibition of oxygen consumption by metformin, with relatively small variation. The expression of OCT1 correlated with expression of both OCT2 and OCT3. OCT1 and OCT2 were relatively uniformly expressed, whereas expression of OCT3, MATE1 and MATE2 showed substantial variation across lines. There were statistically significant associations between resistance to inhibition of proliferation and MATE2 expression, as well as between sensitivity to inhibition of oxygen consumption and OCT3 expression. One cell line (LNCaP) with high OCT3 and low MATE2 expression in concert, had substantially higher intracellular metformin concentration than other cell lines, and was exquisitely sensitive to both anti-proliferative and anti-respiratory effects. In all other cell lines, the concentration of metformin required to inhibit oxygen consumption acutely in vitro was substantially higher than that achieved in the plasma of diabetic patients. However, administering anti-diabetic doses of metformin to tumor-bearing mice resulted in intratumoral accumulation of metformin and reduced hypoxic tumor fractions. CONCLUSIONS: All cancer cells are susceptible to inhibition of oxygen consumption by metformin, which results in reduced hypoxic tumor fractions beneficial for the response to radiotherapy. High MATE2 expression may result in resistance to the anti-proliferative effect of metformin and should be considered as a negative predictive biomarker in clinical trials.

Effects of Combined Treatment with Ionizing Radiation and the PARP Inhibitor Olaparib in BRCA Mutant and Wild Type Patient-Derived Pancreatic Cancer Xenografts.

BACKGROUND: The BRCA2 gene product plays an important role in DNA double strand break repair. Therefore, we asked whether radiation sensitivity of pancreatic cancers developing in individuals with germline BRCA2 mutations can be enhanced by agents that inhibit poly (ADP-ribose) polymerase (PARP). METHODS: We compared the sensitivity of two patient-derived pancreatic cancer xenografts, expressing a truncated or wild type BRCA 2, to ionizing radiation alone or in combination with olaparib (AZD-2281). Animals were treated with either a single dose of 12Gy, 7 days of olaparib or 7 days of olaparib followed by a single dose of 12Gy. Response was assessed by tumour growth delay and the activation of damage response pathways. RESULTS: The BRCA2 mutated and wild type tumours showed similar radiation sensitivity, and treatment with olaparib did not further sensitize either model when compared to IR alone. CONCLUSIONS: While PARP inhibition has been shown to be effective in BRCA-mutated breast and ovarian cancers, it is less well established in pancreatic cancer patients. Our results show no radiosensitization in a germline BRCA 2 mutant and suggest that combining PARP inhibition and IR may not be beneficial in BRCA 2 related pancreatic tumors.

Phase 1/2 Study of the Addition of Cisplatin to Adjuvant Chemotherapy With Image Guided High-Precision Radiation Therapy for Completely Resected Gastric Cancer.

PURPOSE: Locoregional recurrence is common after surgery for gastric cancer. Adjuvant therapy improves outcomes but with toxicity. This phase 1/2 study investigated infusional 5-fluorouracil (5-FU) in combination with biweekly cisplatin delivered concurrently with image guided high-precision radiation therapy. METHODS AND MATERIALS: Eligible patients had completely resected stage IB to IV (Union for International Cancer Control TNM 6th edition) nonmetastatic gastric adenocarcinoma. Treatment constituted 12 weeks of infusional 5-FU (200 mg/m2/day) with cisplatin added in a standard 3 + 3 dose escalation protocol (0, 20, 30, and 40 mg/m2) during weeks 1, 3, 5, and 7, and an additional week 9 dose in the final cohort. Radiation therapy (45 Gy in 25 fractions) was delivered during weeks 3 to 7. Maximum tolerated dose (MTD) was determined in phase 1 and confirmed in phase 2. RESULTS: Among the 55 patients (median age, 54 years; range 28-77 years; 55% male), the median follow-up time was 3.0 years (range, 0.3-5.3 years). Five patients in phase 1 experienced dose-limiting toxicity, and MTD was determined as 4 cycles of 40 mg/m2 cisplatin. Twenty-seven patients were treated at MTD. Acute grade 3 to 4 toxicity rate was 37.0% at MTD and 29.1% across all dose levels. No treatment-related deaths occurred. Fourteen patients experienced recurrent disease. The 2-year overall survival (OS) and relapse-free survival were 85% and 74%, respectively. Median OS has not been reached. Quality of life (QOL) was impaired during treatment, but most scores recovered by 4 weeks. CONCLUSION: Cisplatin can be safely delivered with 5-FU-based chemoradiation therapy. Acute toxicity was acceptable, and patient-reported QOL showed the regimen was tolerable. Outcomes are encouraging and justify further study of this regimen.

A proposal for cellularity assessment for EGFR mutational analysis with a correlation with DNA yield and evaluation of the number of sections obtained from cell blocks for immunohistochemistry in non-small cell lung carcinoma.

AIMS: Different approaches have been described for reporting specimen adequacy for epidermal growth factor receptor (EGFR) mutation analysis. We aimed: (1) to conduct cellularity assessment and to investigate its association with DNA yield, (2) to compare the H&E slides taken before and after the thick sections (curls) obtained for EGFR testing and (3) to evaluate the number of ancillary studies performed. METHODS: Cell block (CB) slides of 110 non-small cell lung carcinoma cases submitted to EGFR analysis from 2010 to 2012 were reviewed for total cellularity (ranges 1-100, 100-250, 250-500, 500-750, 750-1000 and >1000 cells), tumour cellularity (ranges 1-50, 50-100, 100-300 and >300 cells) and the percentage of tumour cells. Precurl and postcurl H&E slides were compared using the three criteria. The number of immunohistochemistry (IHC) markers and special stains and DNA yield were recorded. RESULTS: DNA yield was significantly associated with the total cellularity, number and percentage of tumour cells. For 46 cases with precurl and postcurl slides, only three (6.5%) were classified as being different and in two of them the postcurl slide had greater cellularity than the precurl. IHC was performed in 83 cases, with a minimum of 1 and a maximum of 11 markers (median of 3) per case. CONCLUSIONS: An association between the total cellularity and the tumour cellularity with the DNA yield was demonstrated using the ranges described. Evaluation of a postcurl slide is an unnecessary practice. The majority of the CB had sufficient material for ancillary studies (up to 11 markers) and mutation testing.