Experimental Observation of Plasma Wakefield Growth Driven by the Seeded Self-Modulation of a Proton Bunch

We measure the effects of transverse wakefields driven by a relativistic proton bunch in plasma with densities of 2.1×10^{14} and 7.7×10^{14}  electrons/cm^{3}. We show that these wakefields periodically defocus the proton bunch itself, consistently with the development of the seeded self-modulation process. We show that the defocusing increases both along the bunch and along the plasma by using time resolved and time-integrated measurements of the proton bunch transverse distribution. We evaluate the transverse wakefield amplitudes and show that they exceed their seed value (<15  MV/m) and reach over 300  MV/m. All these results confirm the development of the seeded self-modulation process, a necessary condition for external injection of low energy and acceleration of electrons to multi-GeV energy levels.

Enantioselective Synthesis and Activity of All Diastereoisomers of ( E)-Phytal, a Pheromone Component of the Moroccan Locust, Dociostaurus maroccanus

The Moroccan locust, Dociostaurus maroccanus (Thunberg, 1815) (Orthoptera: Acrididae), is a polyphagous pest capable of inflicting large losses in agriculture under favorable environmental and climatic conditions. Currently, control of the pest relies solely on the application of conventional insecticides that have negative effects on the environment and human safety. In the search for a more rational, environmentally acceptable approach for locust control, we have previously reported that ( Z/ E)-phytal (1) is a male-produced candidate sex pheromone of this acridid. This molecule, with two stereogenic centers at C-7 and C-11, has four different diastereomers along with the Z/ E stereochemistry of the double bond at C-2. In this paper, we present for the first time the enantioselective synthesis of the four diastereomers of ( E)-phytal and their electrophysiological and behavioral activity on males and females. Our results demonstrate that the ( R, R)-phytal is the most active diastereomer in both assays, significantly attracting females in a double-choice Y olfactometer, and confirming the previous chromatographic assignment as component of the sex pheromone of the Moroccan locust.

Sepsis alerts in EMS and the results of pre-hospital ETCO2

BACKGROUND

Field sepsis alerts have the ability to expedite initial ED sepsis treatment. Our hypothesis is that in patients that meet EMS sepsis alert criteria there is a strong relationship between prehospital end-tidal carbon dioxide (ETCO2) readings and the outcome of diagnosed infection.

METHODS

In 2014, our EMS service initiated a protocol requiring hospitals to receive notification of a "sepsis alert" on all suspected sepsis patients. The EMS service transports 70,000 patients/year to a number of urban centers. All patients transported to our major urban teaching hospital by our EMS service in one year in which a sepsis alert was announced were included in this study. The primary outcome variable was diagnosed infection and secondary outcomes were hospital admission, ICU admission and mortality. Positive lactate was defined as >4.0 mmol/L. ROC curve analysis was used to define the best cutoff for ETCO2.

RESULTS

351 patients were announced as EMS sepsis alert patients and transported to our center over a one year period. Positive outcomes were as follows: diagnosed infection in 28% of patients, hospital admission in 63% and ICU admission in 11%. The correlation between lactate and ETCO2 was -0.45. A ROC curve analysis of ETCO2 vs. lactate >4 found that the best cutoff to predict a high lactate was an ETCO2 of 25 or less, which was considered a positive ETCO2 (AUC = 0.73). 27% of patients had a positive ETCO2 and 24% had a positive lactate. A positive ETCO2 predicted a positive lactate with 76% accuracy, 63% sensitivity and 80% specificity. 27% of those with a positive ETCO2 and 44% of those with a positive lactate had a diagnosed infection. 59% of those with a positive ETCO2 and 89% of those with a positive lactate had admission to the hospital. 15% of those with a positive ETCO2 and 18% of those with a positive lactate had admission to the ICU. Neither lactate nor ETCO2 were predictive of an increased risk for diagnosed infection, hospital admission or ICU admission in this patient population.

CONCLUSION

While ETCO2 predicted the initial ED lactate levels it did not predict diagnosed infection, admission to the hospital or ICU admission in our patient population but did predict mortality.

A2A Adenosine Receptor Agonists and their Potential Therapeutic Applications. An Update

BACKGROUND

Adenosine is an endogenous purine nucleoside, which mediates a variety of important biological processes and diseases, such as vasodilation, inflammation, cancer, wound healing, ischemia reperfusion injury, Parkinson disease, infectious diseases, and other CNS disorders. Particularly important are the A2A receptors that have been expressed in the lung, liver, heart, cardiovascular tissues, leukocytes, neutrophils, and endothelial cells. This review provides an update of the latest A2A receptor agonists developed in the period 2005-2017, their selectivity regarding other adenosine receptors and their potential therapeutic applications.

METHODS

I have conducted an extensive search from the most common bibliographic databases for critically review the most recent works on the A2A receptor agonists and their therapeutic applications in inflammation, asthma and chronic obstructive pulmonary disease, myocardial perfusion imaging, sepsis, rheumatoid arthritis, and wound healing, among others.

RESULTS

In the last decade, a great deal of effort has been devoted to develop adenosine receptor agonists and antagonists for treatment of a number of diseases. Thus, for A2A receptor agonists more than 130 papers and reviews have been found, many of them highlighting the usefulness of these compounds in the field.

CONCLUSIONS

Although so far many of the A2A receptor agonists have failed in clinical trials due to their side effects, some of them have been approved for protection against cardiac ischemia-reperfusion injury and anemia. The recently reported crystal structure of the human A2A receptor in complex with the agonist UK-432097 is a fundamental keystone for the development of new and selective A2A ligands with new therapeutic applications.

Behaviour of the Contact Phase of Blood Coagulation in the Adult Respiratory Distress Syndrome (ARDS)

In order to assess the role of the kallikrein-kinin (K-K) system in the pathogenesis of the adult respiratory distress syndrome (ARDS) we have prospectively determined coagulation contact phase, blood gas and hemodynamic parameters in patients with ARDS at 0, 36 and 72 h from diagnosis.

Compared to normal values, significantly lower mean levels of factor XII (71.4 ± 9.8%, p <0.0005), prekallikrein (PPK) (52 ± 5.7%, p <0.0005), high molecular weight kininogen (HMWK) (73 ± 2%, p <0.0005) and α2-macroglobulin (α2-M) (51 ± 7.1%, p <0.0005) were found in ARDS patients.

The functional kallikrein inhibitory activity (KKI) and Cr esterase inhibitor antigenic (CIINH) were significantly higher in these patients (113.2 ± 5, p <0.005 and 124.7 ± 7.6, p <0.0005 respectively) compared with normal values during the entire study period.

The KKI/CIINH ratio decreased significantly in our ARDS patients at 0, 36 and 72 h (p <0.025; p <0.05 and p <0.005 respectively).

We found a significant correlation between PPK levels and oxigenation index (r = 0.69, p <0.001), PPK and the static thoracic compliance values (r = 0.64, p <0.001). There was also a significant correlation between PPK levels and Qs/Qt (r = -0.89, p <0.001). ARDS patients that survived presented a stability in the PPK values in successive tests. Nevertheless non-survivors showed a progressive decrease in PPK levels during the follow-up period.

Our results suggest that the plasma kallikrein system becomes activated during ARDS and that this activation might increase the lung vessels’ permeability. In addition, PPK levels are in our opinion a useful prognostic parameter in predicting the outcome of ARDS patients.

Consumer acceptability of beef from two sexes supplemented with essential oil mix

Essential oils are natural extracts from plants which can be included in cattle diets as an alternative to additives, such as ionophores, to improve the shelf life of meat. The aim of this study was to evaluate the sensory acceptability of meat from 57 crossbred (1/2 Angus–1/2 Nellore) animals of different sexes [heifers n = 30, and young bulls n = 27], finished in feedlot with isoenergetic and isonitrogenous diets, which differed in the level of supplementation (0.0, 3.5 or 7.0 g/animal/day) with a commercial mix of essential oils (Mixoil®) from seven plants: oregano, garlic, lemon, rosemary, thyme, eucalyptus and sweet orange. The Longissimus thoracis muscle, aged for 24 h, was evaluated by 120 consumers who scored tenderness acceptability, flavour acceptability and overall acceptability using a hedonic 9-point scale. The inclusion of essential oils affected tenderness acceptability and flavour acceptability (P ≤ 0.01), with a tendency (P < 0.10) for overall acceptability. Meat from heifers was more appreciated by consumers than that from young bulls in all attributes (P ≤ 0.001), however, different groups of consumers had different preferences. The inclusion of a mix of essential oils in beef diets was well accepted by consumers, and could improve the acceptability of meat from young bulls, when is added at a concentration of 3.5 g/animal/day during the last 4 months of fattening.

A temporal comparison of sex-aggregation pheromone gland content and dynamics of release in three members of the Lutzomyia longipalpis (Diptera: Psychodidae) species complex

Background

Lutzomyia longipalpis is the South American vector of Leishmania infantum, the etiologic agent of visceral leishmaniasis (VL). Male L. longipalpis produce a sex-aggregation pheromone that is critical in mating, yet very little is known about its accumulation over time or factors involved in release. This laboratory study aimed to compare accumulation of pheromone over time and determine factors that might influence release in three members of the L. longipalpis species complex.

Methodology/Principal findings

We investigated male sex-aggregation pheromone gland content at different ages and the release rate of pheromone in the presence or absence of females under different light conditions by gas chromatography-mass spectrometry (GC-MS). Pheromone gland content was determined by extraction of whole males and pheromone release rate was determined by collection of headspace volatiles. Pheromone gland content appeared age-related and pheromone began to accumulate between 6 to 12 h post eclosion and gradually increased until males were 7–9 days old. The greatest amount was detected in 9-day old Campo Grande males ((S)-9-methylgermacrene-B; X ± SE: 203.5 ± 57.4 ng/male) followed by Sobral 2S males (diterpene; 199.9 ± 34.3) and Jacobina males ((1S,3S,7R)-3-methyl-α-himachalene; 128.8 ± 30.3) at 7 days old. Pheromone release was not continuous over time. During a 4-hour period, the greatest quantities of pheromone were released during the first hour, when wing beating activity was most intense. It was then substantially diminished for the remainder of the time. During a 24 h period, 4–5 day old male sand flies released approximately 63 ± 11% of the pheromone content of their glands, depending on the chemotype. The presence of females significantly increased pheromone release rate. The light regime under which the sand flies were held had little influence on pheromone release except on Sobral 2S chemotype.

Conclusions/Significance

Accumulation of pheromone appears to occur at different rates in the different chemotypes examined and results in differing amounts being present in glands over time. Release of accumulated pheromone is not passive, but depends on biotic (presence of females) and abiotic (light) circumstances. There are marked differences in content and release between the members of the complex suggesting important behavioural, biosynthetic and ecological differences between them.

The Dipteran subfamily Phlebotominae includes the genera Lutzomyia and Phlebotomus among which several species are important vectors of parasitic and bacterial pathogens. The sand fly Lutzomyia longipalpis is considered the main vector of visceral leishmaniasis (VL) in the New World. Based on the main component of the male sex-aggregation pheromone gland, different sex pheromone-producing populations (chemotypes) of L. longipalpis are recognized in Brazil. Given the importance of the sex-aggregation pheromones in the biology of this species complex, we present here the first attempt to study how pheromone accumulates in the glands over time and factors that might influence its release in the three most common chemotypes from Brazil. Our results demonstrated that pheromone first starts to accumulate a few hours post-eclosion (6–12 h) and this continues over 15 days. Pheromone release is a dynamic process which varies between the 3 chemotypes depending on biotic factors, such as light regime and presence/absence of conspecific females. This work provides valuable information, critical to our understanding of the behaviour and ecology of L. longipalpis sand flies and which will contribute to investigations to improve field-based pheromone control and monitoring of L. longipalpis sand flies.

Neoadjuvant Therapy with Weekly Nanoparticle Albumin-Bound Paclitaxel for Luminal Early Breast Cancer Patients: Results from the NABRAX Study (GEICAM/2011-02), a Multicenter, Non-Randomized, Phase II Trial, with a Companion Biomarker Analysis

BACKGROUND

Nanoparticle albumin-bound paclitaxel (nab-Paclitaxel) is an alternative to standard taxanes for breast cancer (BC) treatment. We evaluated nab-Paclitaxel efficacy as neoadjuvant treatment for early estrogen receptor-positive (ER+), human epidermal growth factor receptor 2-negative (HER2-) disease.

MATERIALS AND METHODS

Women with ER+, HER2-, stage II-III BC were treated preoperatively with four cycles of weekly nab-Paclitaxel (150 mg/m2), 3 weeks on and 1 week off. We hypothesized that poor pathological response rate (residual cancer burden [RCB] III; Symmans criteria) would be ≤16%.

RESULTS

Eighty-one patients with a median age of 47 years were treated; 64.2% were premenopausal, and 69% of tumors were stage II. Residual cancer burden III rate was 28.4% (95% confidence interval [CI]: 18.6%-38.2%), RCB 0+I (good response) rate was 24.7% (95% CI: 15.3%-34.1%) and RCB 0 (complete response) rate was 7.4% (95% CI: 1.7%-13.1%). Objective response rate by magnetic resonance imaging was 76.5% and rate of conversion to breast conserving surgery was 40.0%. The most frequent grade 3 and 4 toxicity was neutropenia (12.3% and 3.7% of patients, respectively), without any febrile neutropenia. Sensory neuropathy grade 2 and 3 were seen in 25.9% and 2.5% of patients, respectively. Tumor secreted protein, acidic, cysteine-rich (SPARC) overexpression was significantly associated with RCB 0 (odds ratio: 0.079; 95% CI: 0.009-0.689; p = .0216).

CONCLUSION

Despite failing to confirm an RCB III rate ≤16% in nab-Paclitaxel-treated patients, the RCB 0+I rate indicates a significant drug antitumor activity with low rates of grade 3-4 toxicity. Our exploratory biomarker analysis suggests a potential predictive role of complete response for SPARC. Confirmatory analyses are warranted, adapting dose and schedule to decrease peripheral neurotoxicity. (Trial registration: European Clinical Trials Database study number: 2011-004476-10; ClinicalTrials.gov: NCT01565499).

IMPLICATIONS FOR PRACTICE

The pathological response rate (residual cancer burden [RCB]; Symmans criteria) of nanoparticle albumin-bound paclitaxel administered as neoadjuvant treatment for early estrogen receptor-positive, human epidermal growth factor receptor 2-negative disease was evaluated. Whereas poor response (RCB III) was 24.7%, similar to that for docetaxel, good response (RCB 0+I) reached 23.0%, far superior to the 13% for docetaxel, while keeping toxicity low. Exploratory biomarker analysis suggests secreted protein, acidic, cysteine-rich overexpression in tumor cells as a potential predictor of complete response (RCB 0). Findings point to an encouraging single-agent neoadjuvant treatment with low toxicity, which warrants future research and development.

Experience in the treatment of osseous hydatidosis

Osseous hydatidosis is a very uncommon disease which often recurs after treatment. There is no well-established effective method of management. Radical excision may produce serious mutilation and often fails to control the disease. We have used oral mebendazole as adjuvant treatment in four patients. Two also underwent radical excision, one had received limited excision elsewhere and the other did not have operative treatment. The patients who underwent radical excision and the other who did not have an operation became and remain free of symptoms and are serologically negative.A combination of excision and treatment with mebendazole may have a role in the management of this complex disease.

Predictive and prognostic impact of tumour-infiltrating lymphocytes in triple-negative breast cancer treated with neoadjuvant chemotherapy

INTRODUCTION

In locally and locally advanced triple-negative breast cancer (TNBC), neoadjuvant chemotherapy (NAC) only induces a pCR in 30-35% of patients. Clinical and pathological factors are not enough to distinguish the patients who have no chance of a pCR or not. The tumour microenvironment is critical for cancer and tumour-infiltrating lymphocytes (TIL). Moreover, the NAC scenario is the perfect setting to study possible changes in TIL levels.

MATERIAL AND METHODS

Using our prospective maintained breast cancer (BC) database, we identified 164 TNBC patients treated with NAC between 1998 and 2015 with enough samples of diagnostic biopsy and after surgery. Evaluation of TILs before and after NAC followed a standardised methodology for visual assessment on haematoxylin-eosin sections and the amounts of TILs were quantitated in deciles. We categorised lymphocyte-predominant breast cancer cutoff according to a receiver operating characteristic (ROC) analysis. We categorised LPBC as involving > 40% lymphocytic infiltration tumour stroma. The primary end point was predictive value of TILs to NAC, and the secondary end point was disease-free survival (DFS). DFS was analysed using the Kaplan-Meier method and the groups were compared with a long-rank test. Univariate and multivariate Cox models were used to generate hazard ratios for determining associations between variables such as TIL after NAC and DFS.

RESULTS

A total of 164 TNBC patients were treated with NAC and surgery. The main patients' characteristics are listed in Table 1. We identify different pathological complete response to anthracycline and taxane-based NAC; LPBC subgroup 51 from 58 patients (88%) pCR versus non- lymphocyte-predominant breast cancer (LPBC) subgroup 10 from 106 (9%) pCR, p = 0.001. At a median follow-up of 78 months, LPBC was associated with better DFS; the three-year Kaplan-Meier estimates for DFS were 2% and 30 % for patients with LPBC and non-LPBC, respectively, p = 0.01. Univariate and multivariate analysis confirmed TIL to be an independent prognostic marker of DFS.

CONCLUSIONS

Tumour-infiltrating lymphocytes could be routinely used in locally advanced TNBC treated with anthracycline and taxane, such as biomarker, to be enabled the identification of different two subgroups: LPBC patients have a very high response to NAC pCR 88%, meanwhile non-LPBC patients only achieve 9%. Moreover, non-LPBC patients have a worse prognosis than LPBC patients. This data verified the predictive and prognostic value of TIL.

Abstract 3890: Mitochondrial MCL1 maintains triple negative breast cancer stem cells and contributes to chemotherapy resistance

Cytotoxic chemotherapy is the standard of care for patients with triple negative breast cancer (TNBC). Most patients with advanced TNBC progress after chemotherapy and die from metastatic disease. MCL1 is an anti-apoptotic Bcl-2 family member known to sequester and inactivate pro-apoptotic Bcl-2 family proteins and, thus, contribute to chemotherapy resistance. We previously reported that ~45% of residual TNBCs that remain in the breast after neoadjuvant chemotherapy harbor MCL1 amplification, suggesting a causal role for MCL1 in drug resistance. A recent report (Goodwin et al. 2015) suggested that siRNA-mediated ablation of MCL1 does not induce apoptosis in claudin-low TNBC cells with a cancer stem cell (CSC) gene expression signature. CSCs comprise a rare population of cells with tumor-initiating properties and refractoriness to chemotherapy. In this study, we showed that MCL1 expression is elevated in claudin-low TNBC SUM159PT and MDA436 CSCs as measured by ALDH+ by flow cytometry and ability to form mammospheres. RNA interference of MCL1 in SUM159PT cells reduced CSCs and attenuated tumor formation in vivo. Mitochondrial oxidative phosphorylation (mtOXPHOS) plays a crucial role in maintenance of CSCs. MCL1 has been shown to localize in the mitochondrial matrix and contribute to mitochondrial respiration. Thus, we hypothesized that MCL1 contributes to enrichment of TNBC CSCs and chemotherapy resistance via mitochondrial regulation. Stable transfection and overexpression of MCL1 in MDA468 cells increased oxygen consumption ratio, mitochondrial membrane potential, and production of reactive oxygen species (ROS), all features of activated mtOXPHOS. Conversely, RNAi-mediated ablation of MCL1 in SUM159PT and MDA436 cells repressed these markers of activated mtOXPHOS. A mutant of MCL1 lacking its mitochondrial target sequences (MTS) was unable to localize in mitochondria and, when transfected into MDA468 cells, reduced the CD44high/CD24low fraction and mammosphere formation. We next tested VU0659158, a BH3 mimetic in development at Vanderbilt that disrupts MCL1 interactions with BH3 domain-containing proteins, such as BID, BIM, NOXA and PUMA. Treatment of SUM159PT cells with VU0659158 increased caspase activity but did not attenuate mammosphere formation. Analysis of mRNA expression in TCGA revealed that genes induced by mtOXPHOS involved in the hypoxia pathway are significantly up-regulated in MCL1 amplified breast cancers. Finally, pharmacological inhibition of HIF-1α, a key regulator of hypoxia, with digoxin decreased CSCs and attenuated tumor formation in vivo. These data suggest that 1) MCL1 confers resistance to chemotherapy by expanding CSCs via mtOXPHOS independent of its BH3 domain-mediated, anti-apoptotic function, and 2) targeting mitochondrial respiration and the hypoxia pathway may delay or reverse chemotherapy resistance in MCL1 amplified TNBC.

Citation Format: Kyung-min Lee, Jennifer Giltnane, Justin Balko, Luis Schwarz, Angel Guerrero, Katie Hutchinson, Mellissa Hicks, Violeta Sanchez, Melinda Sanders, Taekyu Lee, Edward Olejniczak, Stephen Fesik, Carlos Arteaga. Mitochondrial MCL1 maintains triple negative breast cancer stem cells and contributes to chemotherapy resistance [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3890. doi:10.1158/1538-7445.AM2017-3890

Phase I study to evaluate the tolerability, pharmacokinetics (PK) and pharmacodynamic (PD) of PM01183 (Lurbinectedin) in combination with olaparib in patients with advanced solid tumors

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Background: PM01183 (Lurbinectedin) is a new anticancer drug that exerts antitumor activity through inhibition of trans-activated transcription and modulation of tumor microenvironment and is highly active in platinum resistant ovarian cancer. (Poveda A et al. ASCO 2014.abstr #5505). Olaparib (AZD2281, KU-0059436) is a polyadenosine 5’diphosphoribose (poly [ADP ribose]) polymerase (PARP) inhibitor of PARP-1,-2 and-3 with proven antitumoral activity in homologous recombination deficient tumors. The combination of PM01183 and Olaparib has shown synergistic activity in cell-lines, independent of BRCA mutation status. Methods: This phase I study evaluates the safety, PK and PD of PM1183 in combination with short course of Olaparib tablet formulation [days (d) 1-5] a cycle of 21 d, through a 3+3 dose escalation design (NCT02684318) Patients with advanced or metastatic solid tumors without established standard therapeutic alternatives were selected. Primary endpoints: safety (MTD, DLT and RP2D). Secondary endpoints: PK and PD (western blot analysis of RAD51 and p-gH2AX) profiles at 0h,4.5h, 6.5h and 24h at first cycle of treatment. Results: 20 patients were enrolled from Nov 2015 to Sep 2016 (15 ovarian, 5 endometrial) to 5 dose levels. 19/20 were evaluable for toxicity. Two dose limiting toxicities (DLTs) (both grade 4 neutropenia ≥ 4 days) occurred at the highest dose level (PM01183 2 mg/m2 iv d1 + Olaparib 250 mg [BID] oral on d 1-5. Grade 3 toxicities occurred in 30% of patients, including grade 3 neutropenia (6%) and grade 3 asthenia (10%). PK data are available from 19 patients. Median of PM01183 total clearance (11.0 L/h) is the same as when PM01183 is given as single agent. Clearance of Olaparib (7 L/h) is consistent with results reported elsewhere (5.1 – 8.6 L/h). PD: An overall increase of RAD51 and p-gH2AX was observed, being particularly evident in 56% of patients. Conclusions: The Recommended Dose for Phase II (RP2D) was PM01183 1,5 mg/m2 iv d1 + Olaparib 250 mg BID on d 1-5. This combination is feasible and without evidence of drug-drug interactions. A phase-II study at RP2D is ongoing. Clinical trial information: NCT02684318.

Evaluating the addition of bevacizumab (Bev) to endocrine therapy as first-line treatment for hormone-receptor positive (HR+)/HER2-negative advanced breast cancer (ABC): Pooled-analysis from the LEA (GEICAM/2006-11_GBG51) and CALGB 40503 (Alliance) trials

1012

Background: Data from randomized trials comparing ET v ET-Bev in 1st line HR+/HER2- ABC pts showed controversial results. We performed a pooled-analysis of two randomized trials (LEA and CALGB 40503) to refine the Bev value in this patient population. Methods: We analysed 749 ABC pts with ET (letrozole-673, tamoxifen-39, fulvestrant 250mg-37) +/- Bev. Primary objective was to compare progression-free survival (PFS). Secondary endpoints were: safety; other efficacy (overall response rate [ORR], clinical benefit rate [CBR] and overall survival [OS]) in all pts; and efficacy in de novo pts and by previous endocrine-sensitivity (-/+ 24 months [mo] without recurrence under ET in adjuvant setting). Multivariable Cox models were fitted for PFS adjusted by study co-variables and controlled for study level differences. Results: Median age was 61 years (yr) (range: 25-87); 40% had de novo ABC and 60% recurrent disease (with disease free interval of ≤ 1 yr in 5%, 1-2 yr in 7% and > 2 yr in 88%); 82% of recurrent pts had previous ET sensitivity. Median PFS was 14.3 mo in the ET arm v 19 mo in the ET+Bev arm (HR 0.77; 95% CI 0.66-0.91; p<0.01). ORR and CBR with ET v ET+Bev were 40 v 61% (p<0.01) and 64 v 77% (p<0.01). OS did not differ between arms (HR 0.96; 95% CI 0.77-1.18; p=0.68). PFS for de novo ABC pts was 14.6 and 19.3 mo in the ET and ET+Bev arms (HR 0.82; 95% CI 0.63-1.06; p=0.13). PFS differed between arms for previous sensitive pts (HR 0.68; 95% CI 0.53-0.89; p=0.004) but not for ET-resistant pts (HR 0.73; 95% CI 0.4-1.3; p=0.29). Grade 3-5 hypertension (2.2 v 20.1%), proteinuria (0 v 9.3%), cardiovascular events (0.5 v 4.2%) and liver events (0 v 2.9%) were significantly higher in the ET+Bev arm (all p<0.01). Multivariable analyses showed age (p<0.01), PgR status (p<0.01), type of prior ET (p<0.01) and treatment arm (p<0.01) to be associated with PFS. Conclusions: The addition of Bev to ET increased PFS but not OS. Analyses to define subgroups with prolonged benefit from ET alone or ET-Bev are ongoing. Support: U10CA180821, U10CA180882, Breast Cancer Research Foundation, Genentech, Roche. Clinical trial information: NCT00545077 / NCT00601900.

Genomic alterations driving breast cancer (BC) metastases and their relationship with the subtype switch in the GEICAM ConvertHER study

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Background: To understand the mechanisms underlying the evolution of tumors in the process of metastasis, we studied 61 paired primary-relapse BC from the GEICAM ConvertHER study. While some of the metastases maintained the clinical (ER/PR and HER2 status) and/or intrinsic subtype (defined by expression arrays) of the original tumor (concordant), others exhibited a subtype shift (discordant). We aimed to identify the genomic alterations driving the metastases and, particularly, their relationship with the subtype switch. Methods: We detected the somatic variants (mutations and copy number alterations (CNAs)) affecting 202 genes across the 61 sample pairs via targeted sequencing. We employed the Cancer Genome Interpreter (cancergenomeinterpreter.org), a bioinformatics approach to identify the alterations most likely driving tumorigenesis, and subsequently identified those whose cancer cell fraction markedly changed in the metastases. We explored the clonal remodeling in metastasis comparing the cell fractions of driver mutations in both concordant and discordant tumors. Results: We found that 156 genes had 747 somatic mutations and 171 genes suffered 1042 somatic CNAs in the 61 studied tumor pairs. We identified a median of 11 and 9 mutations in primaries and metastases, respectively. Several frequent BC mutational drivers, such as TP53, PIK3CA, MLL3, MAP3K1, and NOTCH2 were amongst the more frequently changed their cancer cell fraction in metastases with respect to primaries. We found that driver mutations of discordant tumors exhibited a significantly higher increase of clonal cell fraction. Moreover, whether the clonal status of a driver mutation was conserved in the metastasis was significantly associated to whether the tumor maintains its clinical subtype but not its intrinsic subtype. Conclusions: Our results suggest that a shift in the clinical subtype of BC undergoing metastasis is accompanied by more significant changes at the genomic level than those suffered by tumors that maintain their clinical subtype. This remodeling of the landscape of drivers could open new therapeutic opportunities to specifically target discordant BC.