Axillary lymph node dissection versus radiotherapy in breast cancer with positive sentinel nodes after neoadjuvant therapy (ADARNAT trial)

Introduction

Breast cancer surgery currently focuses on de-escalating treatment without compromising patient survival. Axillary radiotherapy (ART) now replaces axillary lymph node dissection (ALND) in patients with limited sentinel lymph node (SLN) involvement during the primary surgery, and this has significantly reduced the incidence of lymphedema without worsening the prognosis. However, patients treated with neoadjuvant systemic treatment (NST) cannot benefit from this option despite the low incidence of residual disease in the armpit in most cases. Data regarding the use of radiotherapy instead of ALND in this population are lacking. This study will assess whether ART is non-inferior to ALND in terms of recurrence and overall survival in patients with positive SLN after NST, including whether it reduces surgery-related adverse effects.

Methods and analyses

This multicenter, randomized, open-label, phase 3 trial will enroll 1660 patients with breast cancer and positive SLNs following NST in approximately 50 Spanish centers over 3 years. Patients will be stratified by NST regimen and nodal involvement (isolated tumoral cells or micrometastasis versus macrometastasis) and randomly assigned 1:1 to ART without ALND (study arm) or ALND alone (control arm). Level 3 and supraclavicular radiotherapy will be added in both arms. The primary outcome is the 5-year axillary recurrence determined by clinical and radiological examination. The secondary outcomes include lymphedema or arm dysfunction, quality of life based (EORTC QLQ-C30 and QLQ-BR23 questionnaires), disease-free survival, and overall survival.

Discussion

This study aims to provide data to confirm the efficacy and safety of ART over ALND in patients with a positive SLN after NST, together with the impact on morbidity.

Ethics and dissemination

The Research Ethics Committee of Bellvitge University Hospital approved this trial (Protocol Record PR148/21, version 3, 1/2/2022) and all patients must provide written informed consent. The involvement of around 50 centers across Spain will facilitate the dissemination of our results.

Trial registration

ClinicalTrials.gov, identifier number NCT04889924.

Fluctuating selection and global change: a synthesis and review on disentangling the roles of climate amplitude, predictability and novelty

A formidable challenge for global change biologists is to predict how natural populations will respond to the emergence of conditions not observed at present, termed novel climates. Popular approaches to predict population vulnerability are based on the expected degree of novelty relative to the amplitude of historical climate fluctuations experienced by a population. Here, we argue that predictions focused on amplitude may be inaccurate because they ignore the predictability of environmental fluctuations in driving patterns of evolution and responses to climate change. To address this disconnect, we review major findings of evolutionary theory demonstrating the conditions under which phenotypic plasticity is likely to evolve in natural populations, and how plasticity decreases population vulnerability to novel environments. We outline key criteria that experimental studies should aim for to effectively test theoretical predictions, while controlling for the degree of climate novelty. We show that such targeted tests of evolutionary theory are rare, with marine systems being overall underrepresented in this venture despite exhibiting unique opportunities to test theory. We conclude that with more robust experimental designs that manipulate both the amplitude and predictability of fluctuations, while controlling for the degree of novelty, we may better predict population vulnerability to climate change.

The effect of omitting axillary dissection and the impact of radiotherapy on patients with breast cancer sentinel node macrometastases: a cohort study following the ACOSOG Z0011 and AMAROS trials

PURPOSE

To report the outcomes of implementing the ACOSOG Z0011 and AMAROS trials relevant to clinical practice, and to define target groups in whom to avoid or recommend axillary radiotherapy (ART). We also aimed to analyse the reduction in morbidity when axillary lymph node dissection (ALND) was omitted.

METHODS

A retrospective cohort study of T1-T2 patients with macrometastases at sentinel lymph node (SLN) who were treated between 2011 and 2020. Breast surgery included either lumpectomy or mastectomy. Patients with ≤ 2 positive SLN were divided into two cohorts by whether they received ART or not. Survival outcomes and morbidity were analysed by Kaplan-Meyer curves and Cox-regression, respectively.

RESULTS

260 pN1a patients were included and ALND was avoided in 167 (64.2%). According the Z0011 results, 72 (43.1%) received no further ART; and based on AMAROS criteria 95 (56.9%) received ART. Median follow-up was 54 months. The 5-year overall survival was 96.8% in the non-RT cohort and 93.4% in the RT cohort (p = 0.19), while the respective 5-year disease-free survivals were 100% and 92.3% (p = 1.06). Lymphedema developed in 3.6% of patients after SLNB versus 43% after ALND (OR 20.25; 95%CI 8.13-50.43). Decreased upper-extremity range of motion appeared in 8.4% of patients after SLNB versus 31.2% after ALND (OR 4.95; 95%CI 2.45-9.98%).

CONCLUSIONS

Our study confirms that omitting ALND is safe and has high survival rates in patients with T1-T2 tumours and ≤ 2 positive SLNs. Adding ART could be a treatment option for patients who present other risk factors. Avoiding ALND with or without ART was associated with significantly less arm morbidity.

Spreading of SARS-CoV-2 in West Africa and assessment of risk factors

Although the African continent is, for the moment, less impacted than the rest of the world, it still faces the risk of a spread of COVID-19. In this study, we have conducted a systematic review of the information available in the literature in order to provide an overview of the epidemiological and clinical features of COVID-19 pandemic in West Africa and of the impact of risk factors such as comorbidities, climatic conditions and demography on the pandemic. Burkina Faso is used as a case study to better describe the situation in West Africa. The epidemiological situation of COVID-19 in West Africa is marked by a continuous increase in the numbers of confirmed cases. This geographic area had on 29 July 2020, 131 049 confirmed cases by polymerase chain reaction, 88 305 recoveries and 2102 deaths. Several factors may influence the SARS-CoV-2 circulation in Africa: (i) comorbidities: diabetes mellitus and high blood pressure could lead to an increase in the number of severe cases of SARS-CoV-2; (ii) climatic factors: the high temperatures could be a factor contributing to slow the spread of the virus and (iii) demography: the West Africa population is very young and this could be a factor limiting the occurrence of severe forms of SARS-CoV-2 infection. Although the spread of the SARS-CoV-2 epidemic in West Africa is relatively slow compared to European countries, vigilance must remain. Difficulties in access to diagnostic tests, lack of hospital equipment, but also the large number of people working in the informal sector (such as trading, businesses, transport and restoration) makes it difficult to apply preventive measures, namely physical distancing and containment.

Evaluation of helper-dependent canine adenovirus vectors in a 3D human CNS model

Gene therapy is a promising approach with enormous potential for treatment of neurodegenerative disorders. Viral vectors derived from canine adenovirus type 2 (CAV-2) present attractive features for gene delivery strategies in the human brain, by preferentially transducing neurons, are capable of efficient axonal transport to afferent brain structures, have a 30-kb cloning capacity and have low innate and induced immunogenicity in preclinical tests. For clinical translation, in-depth preclinical evaluation of efficacy and safety in a human setting is primordial. Stem cell-derived human neural cells have a great potential as complementary tools by bridging the gap between animal models, which often diverge considerably from human phenotype, and clinical trials. Herein, we explore helper-dependent CAV-2 (hd-CAV-2) efficacy and safety for gene delivery in a human stem cell-derived 3D neural in vitro model. Assessment of hd-CAV-2 vector efficacy was performed at different multiplicities of infection, by evaluating transgene expression and impact on cell viability, ultrastructural cellular organization and neuronal gene expression. Under optimized conditions, hd-CAV-2 transduction led to stable long-term transgene expression with minimal toxicity. hd-CAV-2 preferentially transduced neurons, whereas human adenovirus type 5 (HAdV5) showed increased tropism toward glial cells. This work demonstrates, in a physiologically relevant 3D model, that hd-CAV-2 vectors are efficient tools for gene delivery to human neurons, with stable long-term transgene expression and minimal cytotoxicity.

Accuracy of muscle moment arms estimated from MRI-based musculoskeletal models of the lower extremity

OBJECTIVE

Biomechanical models that compute the lengths and moment arms of soft tissues are broadly applicable to the treatment of movement abnormalities and the planning of orthopaedic surgical procedures. The goals of this study were to: (i) develop methods to construct subject-specific biomechanical models from magnetic resonance (MR) images, (ii) create models of three lower-extremity cadaveric specimens, and (iii) quantify the accuracy of muscle-tendon lengths and moment arms estimated using these models.

MATERIALS AND METHODS

Models describing the paths of the medial hamstrings and psoas muscles for a wide range of body positions were developed from MR images in one joint configuration by defining kinematic models of the hip and knee, and by specifying "wrapping surfaces" that simulate interactions between the muscles and underlying structures. Our methods for constructing these models were evaluated by comparing hip and knee flexion moment arms estimated from models of three specimens to the moment arms determined experimentally on the same specimens. Because a muscle's moment arm determines its change in length with joint rotation, these comparisons also tested the accuracy with which the models could estimate muscle-tendon lengths over a range of hip and knee motions.

RESULTS

Errors in the moment arms calculated with the models, averaged over functional ranges of hip and knee flexion, were less than 4 mm (within 10% of experimental values).

CONCLUSION

The combination of MR imaging and graphics-based musculoskeletal modeling provides an accurate and efficient means of estimating muscle-tendon lengths and moment arms in vivo.

Ovarian tumours and other ovarian changes induced in mice by two 19-nor-contraceptives

Images

Granulosa-cell tumours induced in mice by progesterone

Images

Pathological changes induced in the uterus of mice with the prolonged administration of progesterone and 19-nor-contraceptives

Images