A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067

Planets with radii between that of the Earth and Neptune (hereafter referred to as 'sub-Neptunes') are found in close-in orbits around more than half of all Sun-like stars1,2. However, their composition, formation and evolution remain poorly understood3. The study of multiplanetary systems offers an opportunity to investigate the outcomes of planet formation and evolution while controlling for initial conditions and environment. Those in resonance (with their orbital periods related by a ratio of small integers) are particularly valuable because they imply a system architecture practically unchanged since its birth. Here we present the observations of six transiting planets around the bright nearby star HD 110067. We find that the planets follow a chain of resonant orbits. A dynamical study of the innermost planet triplet allowed the prediction and later confirmation of the orbits of the rest of the planets in the system. The six planets are found to be sub-Neptunes with radii ranging from 1.94R⊕ to 2.85R⊕. Three of the planets have measured masses, yielding low bulk densities that suggest the presence of large hydrogen-dominated atmospheres.

Prediction of exercise respiratory limitation from pulmonary function tests

BACKGROUND

Evaluation of unexplained exercise intolerance is best resolved by cardiopulmonary exercise testing (CPET) which enables the determination of the exercise limiting system in most cases. Traditionally, pulmonary function tests (PFTs) at rest are not used for the prediction of a respiratory limitation on CPET.

OBJECTIVE

We sought cut-off values on PFTs that might, a priori, rule-in or rule-out a respiratory limitation in CPET.

METHODS

Patients who underwent CPET in our institute were divided into two groups according to spirometry: obstructive and non-obstructive. Each group was randomly divided 2:1 into derivation and validation cohorts respectively. We analyzed selected PFTs parameters in the derivation groups in order to establish maximal and minimal cut-off values for which a respiratory limitation could be ruled-in or ruled-out. We then validated these values in the validation cohorts.

RESULTS

Of 593 patients who underwent a CPET, 126 were in the obstructive and 467 in the non-obstructive group. In patients with obstructive lung disease, forced expiratory volume in 1 second (FEV1) ≥ 61% predicted could rule out a respiratory limitation, while FEV1 ≤ 33% predicted was always associated with a respiratory limitation. For patients with non-obstructive spirometry, FEV1 of ≥ 73% predicted could rule-out a respiratory limitation. Application of this algorithm might have saved up to 47% and 71% of CPETs in our obstructive and non-obstructive groups, respectively.

CONCLUSION

Presence or absence of a respiratory limitation on CPET can be predicted in some cases based on a PFTs performed at rest.

Management of well appearing infants born to afebrile mothers with inadequate GBS prophylaxis: A retrospective comparison of the three approaches recommended by the COFN

BACKGROUND

There are three different approaches set forth by the Committee on the Fetus and Newborn (COFN) for managing asymptomatic neonates born to mothers with inadequate intrapartum antibiotic prophylaxis (IAP) for early-onset Group B Strep (GBS) infection. The first approach is that of categorical risk factor assessments, and recommends that asymptomatic infants born to afebrile mothers with inadequate IAP for GBS be monitored with clinical observation for 36-48 hours. The second approach recommends serial physical examinations and vital signs for 36-48 hours to closely monitor changes in clinical condition for all patients. The Kaiser Permanente EOS risk calculator (SRC) is an example of the third approach, a multivariate risk assessment, and it takes into consideration several perinatal risk factors. This multivariate risk assessment then provides recommendations for reassessment and management based on presume risk of the infant developing or having Early Onset Sepsis (EOS). The aim of our study was to compare these three recently published recommendations from the COFN for the management of asymptomatic neonates born to afebrile mothers with inadequate IAP for GBS.

STUDY DESIGN

This is a retrospective study of asymptomatic neonates with gestational age ≥35 weeks born to afebrile mothers with indicated inadequate IAP for GBS between April 2017 and July 2020. Management recommendations of the SRC were compared to the recommendations of categorical risk assessment and risk assessment based on clinical condition.

RESULTS

A total of 7,396 infants were born during the study period, 394 (5.3%. to mothers with inadequate IAP. Recommendations for these infants according to both the categorical risk factor guideline and the clinical condition guideline include extended, close observation. However, the SRC recommended routine newborn care for 99.7%.f these infants. None of the infants developed EOS.

CONCLUSION

The SRC recommend routine neonatal care without enhanced and prolonged observation for nearly all asymptomatic infants born to afebrile mothers with inadequate IAP. As none of the infants in this cohort had EOS, further studies in a larger cohort are needed to establish the safety of SRC in neonates born to mothers with inadequate IAP.

Role of Chiral Two-Body Currents in ^{6}Li Magnetic Properties in Light of a New Precision Measurement with the Relative Self-Absorption Technique

A direct measurement of the decay width of the excited 0_{1}^{+} state of ^{6}Li using the relative self-absorption technique is reported. Our value of Γ_{γ,0_{1}^{+}→1_{1}^{+}}=8.17(14)_{stat.}(11)_{syst.}  eV provides sufficiently low experimental uncertainties to test modern theories of nuclear forces. The corresponding transition rate is compared to the results of ab initio calculations based on chiral effective field theory that take into account contributions to the magnetic dipole operator beyond leading order. This enables a precision test of the impact of two-body currents that enter at next-to-leading order.

ΔK=0 M1 Excitation Strength of the Well-Deformed Nucleus ^{164}Dy from K Mixing

The size of a ΔK=0 M1 excitation strength has been determined for the first time in a predominantly axially deformed even-even nucleus. It has been obtained from the observation of a rare K-mixing situation between two close-lying J^{π}=1^{+} states of the nucleus ^{164}Dy with components characterized by intrinsic projection quantum numbers K=0 and K=1. Nuclear resonance fluorescence induced by quasimonochromatic linearly polarized γ-ray beams provided evidence for K mixing of the 1^{+} states at 3159.1(3) and 3173.6(3) keV in excitation energy from their γ-decay branching ratios into the ground-state band. The ΔK=0 transition strength of B(M1;0_{1}^{+}→1_{K=0}^{+})=0.008(1)μ_{N}^{2} was inferred from a mixing analysis of their M1 transition rates into the ground-state band. It is in agreement with predictions from the quasiparticle phonon nuclear model. This determination represents first experimental information on the M1 excitation strength of a nuclear quantum state with a negative R-symmetry quantum number.

Long-Term Venovenous Connection for Extracorporeal Carbon Dioxide Removal (ECCO2R)-Numerical Investigation of the Connection to the Common Iliac Veins

Purpose

Currently used cannulae for extracorporeal carbon dioxide removal (ECCO₂R) are associated with complications such as thrombosis and distal limb ischemia, especially for long-term use. We hypothesize that the risk of these complications is reducible by attaching hemodynamically optimized grafts to the patient’s vessels. In this study, as a first step towards a long-term stable ECCO₂R connection, we investigated the feasibility of a venovenous connection to the common iliac veins. To ensure its applicability, the drainage of reinfused blood (recirculation) and high wall shear stress (WSS) must be avoided.

Methods

A reference model was selected for computational fluid dynamics, on the basis of the analysis of imaging data. Initially, a sensitivity analysis regarding recirculation was conducted using as variables: blood flow, the distance of drainage and return to the iliocaval junction, as well as the diameter and position of the grafts. Subsequently, the connection was optimized regarding recirculation and the WSS was evaluated. We validated the simulations in a silicone model traversed by dyed fluid.

Results

The simulations were in good agreement with the validation measurements (mean deviation 1.64%). The recirculation ranged from 32.1 to 0%. The maximum WSS did not exceed 5.57 Pa. The position and diameter of the return graft show the highest influence on recirculation. A correlation was ascertained between recirculation and WSS. Overall, an inflow jet directed at a vessel wall entails not only high WSS, but also a flow separation and thereby an increased recirculation. Therefore, return grafts aligned to the vena cava are crucial.

Conclusion

In conclusion, a connection without recirculation could be feasible and therefore provides a promising option for a long-term ECCO₂R connection.

Shape transitions between and within Zr isotopes

The Zirconium isotopes across the N=56,58 neutron sub­shell closures have been of special interest since years, sparked by the near doubly-magic features of 96Zr and the subsequent rapid onset of collectivity with a deformed ground-state structure already in 100Zr. Recent state-of-the-art shell model approaches did not only correctly describe this shape-phase transition in the Zr isotopic chain, but alsothe coexistence of non-collective structures and pronounced collectivity especially in 96,98Zr. Theisotope 98Zr is located on the transition from spherical to deformed ground state structures. We summarize recent experimental work to obtain the B(E2) excitation strengths of the first 2+ state of98Zr, including a new experiment employing the recoil-distance Doppler-shift method following a two-neutron transfer reaction.

A stochastic microstructure model for particle reinforced aluminium matrix composites

Metal matrix composites are complex materials consisting of various phases which can display largely different mechanical properties. The deformation behaviour of these composites cannot be sufficiently modelled by averages or simple particle shapes due to the local stresses that occur on the particle edges. Therefore, a sophisticated model of the microstructure is needed. We introduce a method for stochastic modelling of a silicon carbide (SiC) particle reinforced aluminium matrix composite. The SiC particles are modelled by Laguerre polyhedra generated by densely packed spheres. The shape factors of the polyhedra have been fitted to the particle shapes observed in three-dimensional images. Particle elongation in extrusion direction and the observed log-normal volume distribution of the particles are included in the model by suitable scaling. An outlook is presented on how to model the grains of the polycrystalline aluminium matrix and intermetallic precipitates, which result from the strengthening mechanism of the matrix. LAY DESCRIPTION: Metal matrix composites are complex materials consisting of different phases which can display largely different mechanical properties. The deformation behaviour of these composites cannot be sufficiently modelled by averages or simple particle shapes due to the local stresses that occur on the particle edges. Therefore, a sophisticated model of the microstructure is needed. We introduce a method of stochastic modelling of a silicon carbide (SiC) particle reinforced aluminium matrix composite. The SiC particles are modelled by Laguerre polyhedra generated by densely packed spheres. The shape factors of the polyhedra have been fitted to the SiC shapes observed in three-dimensional images. Additionally, the polyhedra are scaled anisotropically to account for orientation anisotropy and to obtain a log-normal volume distribution. An outlook is presented on how to model the aluminium phase's grains and intermetallic precipitates, which result from the strengthening mechanism of the aluminium matrix alloy.

Effect of pre-operative methylprednisolone on orthostatic hypotension during early mobilization after total hip arthroplasty

BACKGROUND

Orthostatic hypotension (OH) and intolerance (OI) are common after total hip arthroplasty (THA) and may delay early mobilization. The pathology of OH and OI includes a dysregulated post-operative vasopressor response, by a hitherto unknown mechanism. We hypothesized that OI could be related to the inflammatory stress response which is inhibited by steroid administration. Consequently, this study evaluated the effect of a pre-operative high-dose methylprednisolone on OH and OI early after THA.

METHODS

Randomized, double-blind, placebo-controlled study in 59 patients undergoing elective unilateral THA with spinal anesthesia and a standardized multimodal analgesic regime. Patients were allocated (1 : 1) to pre-operative intravenous (IV) methylprednisolone (MP) 125 mg or isotonic saline (C). OH, OI and cardiovascular responses to sitting and standing were evaluated using a standardized mobilization protocol pre-operatively, 6, and 24 h after surgery. Systolic and diastolic arterial pressure and heart rate were measured non-invasively (Nexfin^® ). The systemic inflammation was monitored by the C-reactive protein (CRP) response.

RESULTS

At 6 h post-operatively, 11 (38%) versus 11 (37%) patients had OH in group MP and group C, respectively (RR 1.02 (0.60 to 1.75; P = 1.00)), whereas OI was present in 9 (31%) versus 13 (43%) patients (RR 0.76 (0.42 to 1.36; P = 0.42)), respectively. At 24 h post-operatively, the prevalence of OH and OI did not differ between groups, though CRP levels were significantly reduced in group MP (P < 0.001).

CONCLUSION

Pre-operative administration of 125 mg methylprednisolone IV did not reduce OH or OI compared with placebo despite a reduced inflammatory response.

Shell Evolution and E2 Collectivity: New Spectroscopic Information

New spectroscopic information on electric quadrupole collectivity has recently been obtained. We report on our identification of a coexisting deformed structure in the quasi-doubly closed-shell nucleus 96Zr from our measurement of a corresponding absolute E2 intraband transition strength in electron scattering reactions and its small mixing matrix element with the spherical ground state structure. The even-mass zirconium isotopes exhibit a first order quantum shape phase transition between neutron numbers 58 and 60. We have used photon scattering reactions for a first measurement of the E2 decay strength of the nuclear 1+ scissors mode. Evidence for its 2+ rotational excitation and its extraordinarily large rotational moment of inertia are presented.

E2 decay strength of the M1 scissors mode of ^{156}Gd and its first excited rotational state

The E2/M1 multipole mixing ratio δ_{1→2} of the 1_{sc}^{+}→2_{1}^{+} γ-ray decay in ^{156}Gd and hence the isovector E2 transition rate of the scissors mode of a well-deformed rotational nucleus has been measured for the first time. It has been obtained from the angular distribution of an artificial quasimonochromatic linearly polarized γ-ray beam of energy 3.07(6) MeV scattered inelastically off an isotopically highly enriched ^{156}Gd target. The data yield first direct support for the deformation dependence of effective proton and neutron quadrupole boson charges in the framework of algebraic nuclear models. First evidence for a low-lying J^{π}=2^{+} member of the rotational band of states on top of the 1^{+} band head is obtained, too, indicating a significant signature splitting in the K=1 scissors mode rotational band.

Whole-Body Diffusion Imaging Applying Simultaneous Multi-Slice Excitation

PURPOSE

The purpose of this study was to examine the feasibility of a fast protocol for whole-body diffusion-weighted imaging (WB-DWI) using a slice-accelerated echo-planar sequence, which, when using comparable image acquisition parameters, noticeably reduces measurement time compared to a conventional WB-DWI protocol.

MATERIALS AND METHODS

A single-shot echo-planar imaging sequence capable of simultaneous slice excitation and acquisition was optimized for WB-DWI on a 3 T MR scanner, with a comparable conventional WB-DWI protocol serving as the reference standard. Eight healthy individuals and one oncologic patient underwent WB-DWI. Quantitative analysis was carried out by measuring the apparent diffusion coefficient (ADC) and its coefficient of variation (CV) in different organs. Image quality was assessed qualitatively by two independent radiologists using a 4-point Likert scale.

RESULTS

Using our proposed protocol, the scan time of the WB-DWI measurement was reduced by up to 25.9 %. Both protocols, the slice-accelerated protocol and the conventional protocol, showed comparable image quality without statistically significant differences in the reader scores. Similarly, no significant differences of the ADC values of parenchymal organs were found, whereas ADC values of brain tissue were slightly higher in the slice-accelerated protocol.

CONCLUSION

It was demonstrated that slice-accelerated DWI can be applied to WB-DWI protocols with the potential to greatly reduce the required measurement time, thereby substantially increasing clinical applicability.

KEY POINTS

•Whole-body diffusion-weighted imaging (WB-DWI) using simultaneous multi-slice and blipped-CAIPIRINHA reduces the measurement time strongly without having a significant impact on image quality. •The reduction in measurement time might strongly contribute to the clinical applicability of WB-DWI. •However, further refinement of the slice-accelerated EPI sequence, and the WB-DWI protocol applying this sequence type seems necessary; and the value of such WB-DWI protocols for assessment of systemic oncological diseases needs to be investigated in further clinical studies.

Overview of the ARGOS X-ray framing camera for Laser MegaJoule

Commissariat à l'Énergie Atomique et aux Énergies Alternatives has developed the ARGOS X-ray framing camera to perform two-dimensional, high-timing resolution imaging of an imploding target on the French high-power laser facility Laser MegaJoule. The main features of this camera are: a microchannel plate gated X-ray detector, a spring-loaded CCD camera that maintains proximity focus in any orientation, and electronics packages that provide remotely-selectable high-voltages to modify the exposure-time of the camera. These components are integrated into an "air-box" that protects them from the harsh environmental conditions. A miniaturized X-ray generator is also part of the device for in situ self-testing purposes.

Survival after neoadjuvant chemotherapy with or without bevacizumab or everolimus for HER2-negative primary breast cancer (GBG 44-GeparQuinto)†

BACKGROUND

The GeparQuinto study showed that adding bevacizumab to 24 weeks of anthracycline-taxane-based neoadjuvant chemotherapy increases pathological complete response (pCR) rates overall and specifically in patients with triple-negative breast cancer (TNBC). No difference in pCR rate was observed for adding everolimus to paclitaxel in nonearly responding patients. Here, we present disease-free (DFS) and overall survival (OS) analyses.

PATIENTS AND METHODS

Patients (n = 1948) with HER2-negative tumors of a median tumor size of 4 cm were randomly assigned to neoadjuvant treatment with epirubicin/cyclophosphamide followed by docetaxel (EC-T) with or without eight infusions of bevacizumab every 3 weeks before surgery. Patients without clinical response to EC ± Bevacizumab were randomized to 12 weekly cycles paclitaxel with or without everolimus 5 mg/day. To detect a hazard ratio (HR) of 0.75 (α = 0.05, β = 0.8) 379 events had to be observed in the bevacizumab arms.

RESULTS

With a median follow-up of 3.8 years, 3-year DFS was 80.8% and 3-year OS was 89.7%. Outcome was not different for patients receiving bevacizumab (HR 1.03; P = 0.784 for DFS and HR 0.974; P = 0.842 for OS) compared with patients receiving chemotherapy alone. Patients with TNBC similarly showed no improvement in DFS (HR = 0.99; P = 0.941) and OS (HR = 1.02; P = 0.891) when treated with bevacizumab. No other predefined subgroup (HR+/HER2-; locally advanced (cT4 or cN3) or not; cT1-3 or cT4; pCR or not) showed a significant benefit. No difference in DFS (HR 0.997; P = 0.987) and OS (HR 1.11; P = 0.658) was observed for nonearly responding patients receiving paclitaxel with or without everolimus overall as well as in subgroups.

CONCLUSIONS

Long-term results, in opposite to the results of pCR, do not support the neoadjuvant use of bevacizumab in addition to an anthracycline-taxane-based chemotherapy or everolimus in addition to paclitaxel for nonearly responding patients.

CLINICAL TRIAL NUMBER

NCT 00567554, www.clinicaltrials.gov.

Medical preparedness, incidents, and group dynamics during the analog MARS2013 mission

Participants on spaceflights and international scientific analog Mars missions can encounter medical incidents (accidents, illnesses) and psychological issues (e.g., stress, group interaction, sleep disturbance, emotions). The aim of this study was to examine these parameters in a field crew living in a desert environment similar to Mars (Group 1) and in Mission Support Center (MSC) personnel on "Earth" (Group 2) during a 4-week mission. Of the 107 medical interventions in the field, 73 mainly minor incidents together with four near accidents and 29 medical checkup interventions were recorded. Of the 32 medical interventions, medical treatments for 23 incidents of minor severity were necessary in Group 2. Injuries (Group 1: 1.4/100 h, Group 2: 0.1/100 h) were significantly increased in the field, and illnesses (Group 1: 0.3/100 h, Group 2: 3.0/100 h) in the MSC personnel. Causes of accidents and illnesses are described. Psychological results show that emotions and stress remained stable in both groups. Sympathy, social competence, teamwork, and leadership showed high scores. These scores were lower on "Earth" but significantly increased in the last weeks. The Sahara's nighttime coldness was reflected in an increased wake-up frequency, and a longer sleeping time peaked in the third week, probably as a result of overfatigue. MARS2013 was a successful mission with highly motivated participants and minor medical incidents. For future analog missions and possibly long-distance open-space missions, some recommendations in terms of medical and psychological preparedness are made to reduce risks for field crew members and MSC personnel.

Opioid maintenance therapy in Switzerland: an overview of the Swiss IMPROVE study

BACKGROUND/AIMS

Switzerland's drug policy model has always been unique and progressive, but there is a need to reassess this system in a rapidly changing world. The IMPROVE study was conducted to gain understanding of the attitudes and beliefs towards opioid maintenance therapy (OMT) in Switzerland with regards to quality and access to treatment. To obtain a "real-world" view on OMT, the study approached its goals from two different angles: from the perspectives of the OMT patients and of the physicians who treat patients with maintenance therapy. The IMPROVE study collected a large body of data on OMT in Switzerland. This paper presents a small subset of the dataset, focusing on the research design and methodology, the profile of the participants and the responses to several key questions addressed by the questionnaires.

METHODS

IMPROVE was an observational, questionnaire-based cross-sectional study on OMT conducted in Switzerland. Respondents consisted of OMT patients and treating physicians from various regions of the country. Data were collected using questionnaires in German and French. Physicians were interviewed by phone with a computer-based questionnaire. Patients self-completed a paper-based questionnaire at the physicians' offices or OMT treatment centres.

RESULTS

A total of 200 physicians and 207 patients participated in the study. Liquid methadone and methadone tablets or capsules were the medications most commonly prescribed by physicians (60% and 20% of patient load, respectively) whereas buprenorphine use was less frequent. Patients (88%) and physicians (83%) were generally satisfied with the OMT currently offered. The current political framework and lack of training or information were cited as determining factors that deter physicians from engaging in OMT. About 31% of OMT physicians interviewed were ≥60 years old, indicating an ageing population. Diversion and misuse were considered a significant problem in Switzerland by 45% of the physicians.

CONCLUSION

The subset of IMPROVE data presented gives a present-day, real-life overview of the OMT landscape in Switzerland. It represents a valuable resource for policy makers, key opinion leaders and drug addiction researchers and will be a useful basis for improving the current Swiss OMT model.

Ten-year analysis of the prospective multicentre Chemo-N0 trial validates American Society of Clinical Oncology (ASCO)-recommended biomarkers uPA and PAI-1 for therapy decision making in node-negative breast cancer patients

AIM

Final 10-year analysis of the prospective randomised Chemo-N0 trial is presented. Based on the Chemo-N0 interim results and an European Organisation for Research and Treatment of Cancer (EORTC) pooled analysis (n=8377), American Society of Clinical Oncology (ASCO) and Arbeitsgemeinschaft Gynäkologische Onkologie (AGO) guidelines recommend invasion and metastasis markers urokinase-type plasminogen activator (uPA)/plasminogen activator inhibitor-1 (PAI-1) for risk assessment and treatment decision in node-negative (N0) breast cancer (BC).

METHODS

The final Chemo-N0 trial analysis (recruitment 1993-1998; n=647; 12 centres) comprises 113 (5-167) months of median follow-up. Patients with low-uPA and PAI-1 tumour tissue levels (n=283) were observed. External quality assurance guaranteed uPA/PAI-1 enzyme-linked immunosorbent assay (ELISA) standardisation. Of 364 high uPA and/or PAI-1 patients, 242 agreed to randomisation for CMF chemotherapy (n=117) versus observation (n=125).

RESULTS

Actuarial 10-year recurrence rate (without any adjuvant systemic therapy) for high-uPA/PAI-1 observation group patients (randomised and non-randomised) was 23.0%, in contrast to only 12.9% for low-uPA/PAI-1 patients (plog-rank=0.011). High-risk patients randomised to cyclophosphamide-methotrexate-5-fluorouracil (CMF) therapy had a 26.0% lower estimated probability of disease recurrence than those randomised for observation (intention-to-treat (ITT)-analysis: hazard ratio (HR) 0.74 (0.44-1.27); plog-rank=0.28). Per-protocol analysis demonstrated significant treatment benefit: HR 0.48 (0.26-0.88), p=0.019, disease-free survival (DFS) Cox regression, adjusted for tumour stage and grade.

CONCLUSIONS

Chemo-N0 is the first prospective biomarker-based therapy trial in early BC defining patients reaching good long-term DFS without adjuvant systemic therapy. Using a standardised uPA/PAI-1 ELISA, almost half of N0-patients could be spared chemotherapy, while high-risk patients benefit from adjuvant chemotherapy. These 10-year results validate the long-term prognostic impact of uPA/PAI-1 and the benefit from adjuvant chemotherapy in the high-uPA/PAI-1 group at highest level of evidence. They thus support the guideline-based routine use of uPA/PAI-1 for risk-adapted individualised therapy decisions in N0 breast cancer.

Abstract P2-10-25: Prognostic value of relative change in tumor marker CA 27.29 in early stage breast cancer – The SUCCESS trial

Background: MUC1 based tumor markers like CA27.29 (TM) in breast cancer are routinely used in metastatic disease as early marker for treatment efficacy. However, in early stage disease data is sparse. In this analysis, we looked at the impact of individual change in CA27.29 on prognosis instead of using a threshold.

Methods: The SUCCESS Trial compares FEC-docetaxel (Doc) vs. FEC-Doc-Gemcitabine (Doc-G) regime and two vs. five year treatment with Zoledronat in 3754 patients (pts) with primary breast cancer (N+ or high risk N0). We measured CA27.29 after surgery but before chemotherapy (CHT) as baseline and compared it to CA27.29 levels 2 years thereafter with the ST AIA-PACK Ca27.29 reagent using MUC-1 for AIA-600II (Tosoh Bioscience, Tessenderlo, Belgium).

Results: CA27.29 data is available of 2,015 pts. 119 pts (5.9%) had TM over the threshold of 32U/ml before CHT and 56 (2.8%) 2years thereafter. To examine the relative change of tumor marker, pts were divided into 3 groups:

increase: change &gt;=5 U/ml; stable: change &lt;±5U/ml; decrease: change &gt; = −5 U/ml.

123 (6.1%) pts had increasing (&gt;=5 U/ml), 1419 (70.4%) had stable, 473 (23.5%) had decreasing TM levels from before CHT to 2 years thereafter. The majority of pts with increasing TM (86 pts; 69.9%) had levels below the usual threshold of 32U/ml at all times. Patients with an increase &gt;=5 U/ml had an 81% increased risk for recurrence (HR = 1.810 [CI: 1.111–2.948]) and reduced overall survival (HR = 1.020 [CI: 1.004–1.037]). In the multivariate analysis taking into account tumor size, nodal status, grading, age, hormonal and HER2/neu receptor status increasing CA27.29 levels were an independent prognostic marker.

Conclusions: An increase of the tumor marker CA27.29 2 years after CHT compared to pre-chemotherapy baseline was associated with a worse prognosis. By using this approach, more patients at risk for recurrence were detected than with the standard threshold approach. Therefore, the use of relative change could help to identify more patients at risk for relapse who might benefit from an intensified follow up.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P2-10-25.

P4-07-06: Correlation of Two Analytical Methods for Circulating Tumor Cells in Peripheral Blood of Patients with Primary Breast Cancer

Background

While the evidence for circulating tumor cells (CTCs) as a prognostic marker in metastatic breast cancer has been well established, there is still a lack of data in primary disease. In the SUCCESS A trial two different techniques for the detection of CTCs in early breast cancer were prospectively evaluated.

Material and Methods: SUCCESS A compared FEC-Docetaxel vs. FEC-Docetaxel-Gemcitabine and 5 vs. 2 years of treatment with zoledronic acid in primary breast cancer patients and node positive or high-risk node negative disease. Two different techniques to detect CTCs were prospectively evaluated in two consecutive, but comparable subgroups of the whole study population.

In 3515 samples the CellSearch® System (Veridex, Warren, USA) was used for CTC detection. Immunomagnetic enrichment with an EPCAM-antibody was followed by labeling with monoclonal antibodies specific for cytokeratin (8, 18, 19) and leukocytes (CD45). 2165 samples were evaluated with a manual immunocytochemistry (MICC) protocol. Cytospins were prepared after mononuclear cell enrichment based on Oncoquick® centrifugation (greiner bio-one, Frickenhausen, Germany). Staining was performed with the monoclonal pancytokeratin antibody A45-B/B3 (Micromet, Munich, Germany) and the APAAP technique. Conventional light field microscopy (Axiophot; Zeiss, Oberkochen, Germany) was used for the detection of stained cells.

For both methods, the cut-off value for positivity was ≥ 1 CTC. All events were evaluated by two independent observers.

Results: CTCs were examined in a total number of 3243 patients before and after chemotherapy (CHT). The two subgroups evaluated with one or the other method were well-balanced regarding clinical parameters as tumor size, grading, lymph node-status, hormone receptors and Her2. Furthermore there was no significant correlation between the CTC positivity and one of these clinical parameters using CellSearch or the MICC, respectively (p &gt; 0,05 using the chi square test each time).

Before adjuvant CHT 21. 3% (424 out of 1994) and 21.1 % (264 out of 1249) of the patients were found positive for CTCs using CellSearch® or the MICC respectively, with a mean CTC level of 5.9 (range: 1 to 827) and 3.1 (range: 1 to 256).

Immediately after CHT 21.9% (333 out of 1521) and 16.5% (151 out of 916) of the patients were positive for CTCs using CellSearch® or the MICC. The mean CTC level decreased to 3.0 (range: 1 to 124) and 2.1 (range: 1 to 23) in both analytical methods.

Using CellSearch® there was a significant correlation between the presence of CTCs before CHT and disease progression (p = 0.0044), as well as survival (p = 0.0001), whereas the MICC did not predict any of these (p = 0.3143 and p = 0.0801 respectively; the chi-square test was used each time).

Conclusion: We found comparable prevalence of CTCs before and after adjuvant chemotherapy both with the CellSearch® System or the MICC. However, prognostic relevance could only be shown for CTCs detected with the CellSearch® System. This may be attributed to the high standardization and reproducibility of the automated system, as well as the additional CD45 counterstaining. According to our findings, the FDA approved CellSearch® System should be used as gold standard for CTC detection in future clinical trials.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P4-07-06.

International standardisation work on the measurement of radon in air and water

Radon is considered to be the main source of human exposure to natural radiation. As stated by the World Health Organization, the exposure due to the inhalation of indoor radon is much greater than the one via the ingestion of water as radon degasses from water during handling. In response to these concerns about the universal presence of radon, environmental assessment studies are regularly commissioned to assess the radon exposure of public and workers. The credibility of such studies relies on the quality and reliability of radon analysis as well as on the sample representativeness of the radiological situation. The standard-setting approach, based on consensus, seemed to lend itself to a settlement of technical aspects of potential comparison. At present, two Working Groups of the International Standardization Organization are focussing on drafting standards on radon and its decay products measurement in air and water. These standards, which aim for a set of rigorous metrology practices, will be useful for persons in charge of the initial characterisation of a site with respect to natural radioactivity as well as to those performing the routine surveillance of specific sites.