Similarity between structural and proxy estimates of brain connectivity

Functional magnetic resonance and diffusion weighted imaging have so far made a major contribution to delineation of the brain connectome at the macroscale. While functional connectivity (FC) was shown to be related to structural connectivity (SC) to a certain degree, their spatial overlap is unknown. Even less clear are relations of SC with estimates of connectivity from inter-subject covariance of regional F18-fluorodeoxyglucose uptake (FDGcov) and grey matter volume (GMVcov). Here, we asked to what extent SC underlies three proxy estimates of brain connectivity: FC, FDGcov and GMVcov. Simultaneous PET/MR acquisitions were performed in 56 healthy middle-aged individuals. Similarity between four networks was assessed using Spearman correlation and convergence ratio (CR), a measure of spatial overlap. Spearman correlation coefficient was 0.27 for SC-FC, 0.40 for SC-FDGcov, and 0.15 for SC-GMVcov. Mean CRs were 51% for SC-FC, 48% for SC-FDGcov, and 37% for SC-GMVcov. These results proved to be reproducible and robust against image processing steps. In sum, we found a relevant similarity of SC with FC and FDGcov, while GMVcov consistently showed the weakest similarity. These findings indicate that white matter tracts underlie FDGcov to a similar degree as FC, supporting FDGcov as estimate of functional brain connectivity.

Network structure-function coupling and neurocognition in cerebral small vessel disease

BACKGROUND

Cerebral small vessel disease is a leading cause of cognitive decline and vascular dementia. Small vessel disease pathology changes structural brain networks, but its impact on functional networks remains poorly understood. Structural and functional networks are closely coupled in healthy individuals, and decoupling is associated with clinical symptoms in other neurological conditions. We tested the hypothesis that structural-functional network coupling is related to neurocognitive outcomes in 262 small vessel disease patients.

METHODS

Participants underwent multimodal magnetic resonance imaging and cognitive assessment in 2011 and 2015. Structural connectivity networks were reconstructed using probabilistic diffusion tractography, while functional connectivity networks were estimated from resting-state functional magnetic resonance imaging. Structural and functional networks were then correlated to calculate a measure of structural-functional network coupling for each participant.

RESULTS

Lower whole-brain coupling was associated with reduced processing speed and greater apathy both cross-sectionally and longitudinally. In addition, coupling within the cognitive control network was associated with all cognitive outcomes, suggesting that neurocognitive outcomes in small vessel disease may be related to the functioning of this intrinsic connectivity network.

CONCLUSIONS

Our work demonstrates the influence of structural-functional connectivity network decoupling in small vessel disease symptomatology. Cognitive control network function may be investigated in future studies.

Sex differences of vascular brain lesions in patients with atrial fibrillation

Objective

To examine sex differences in prevalence, volume and distribution of vascular brain lesions on MRI among patients with atrial fibrillation (AF).

Methods

In this cross-sectional analysis, we included 1743 patients with AF (27% women) from the multicentre Swiss Atrial Fibrillation study (SWISS-AF) with available baseline brain MRI. We compared presence and total volume of large non-cortical or cortical infarcts (LNCCIs), small non-cortical infarcts, microbleeds (MB) and white matter hyperintensities (WMH, Fazekas score ≥2 for moderate or severe degree) between men and women with multivariable logistic regression. We generated voxel-based probability maps to assess the anatomical distribution of lesions.

Results

We found no strong evidence for an association of female sex with the prevalence of all ischaemic infarcts (LNCCI and SNCI combined; adjusted OR 0.86, 95% CI 0.67 to 1.09, p=0.22), MB (adjusted OR 0.91, 95% CI 0.68 to 1.21, p=0.52) and moderate or severe WMH (adjusted OR 1.15, 95% CI 0.90 to 1.48, p=0.27). However, total WMH volume was 17% larger among women than men (multivariable adjusted multiplicative effect 1.17, 95% CI 1.01 to 1.35; p=0.04). Lesion probability maps showed a right hemispheric preponderance of ischaemic infarcts in both men and women, while WMH were distributed symmetrically.

Conclusion

Women had higher white matter disease burden than men, while volume and prevalence of other lesions did not differ. Our findings highlight the importance of controlling risk factors for cerebral small vessel disease in patients with AF, especially among women.

Cerebral small vessel disease burden and cognitive and functional outcomes after stroke: A multicenter prospective cohort study

INTRODUCTION

It remains unknown whether the global small vessel disease (SVD) burden predicts post-stroke outcomes.

METHODS

In a prospective multicenter study of 666 ischemic and hemorrhagic stroke patients, we quantified magnetic resonance imaging (MRI)-based SVD markers (lacunes, white matter hyperintensities, microbleeds, perivascular spaces) and explored associations with 6- and 12-month cognitive (battery of 15 neuropsychological tests) and functional (modified Rankin scale) outcomes.

RESULTS

A global SVD score (range 0-4) was associated with cognitive impairment; worse performance in executive function, attention, language, and visuospatial ability; and worse functional outcome across a 12-month follow-up. Although the global SVD score did not improve prediction, individual SVD markers, assessed across their severity range, improved the calibration, discrimination, and reclassification of predictive models including demographic, clinical, and other imaging factors.

DISCUSSION

SVD presence and severity are associated with worse cognitive and functional outcomes 12 months after stroke. Assessing SVD severity may aid prognostication for stroke patients.

HIGHLIGHTS

In a multi-center cohort, we explored associations of small vessel disease (SVD) burden with stroke outcomes. SVD burden associates with post-stroke cognitive and functional outcomes. A currently used score of SVD burden does not improve the prediction of poor outcomes. Assessing the severity of SVD lesions adds predictive value beyond known predictors. To add predictive value in assessing SVD in stroke patients, SVD burden scores should integrate lesion severity.

Machine learning analysis of whole mouse brain vasculature

Tissue clearing methods enable the imaging of biological specimens without sectioning. However, reliable and scalable analysis of large imaging datasets in three dimensions remains a challenge. Here we developed a deep learning-based framework to quantify and analyze brain vasculature, named Vessel Segmentation & Analysis Pipeline (VesSAP). Our pipeline uses a convolutional neural network (CNN) with a transfer learning approach for segmentation and achieves human-level accuracy. By using VesSAP, we analyzed the vascular features of whole C57BL/6J, CD1 and BALB/c mouse brains at the micrometer scale after registering them to the Allen mouse brain atlas. We report evidence of secondary intracranial collateral vascularization in CD1 mice and find reduced vascularization of the brainstem in comparison to the cerebrum. Thus, VesSAP enables unbiased and scalable quantifications of the angioarchitecture of cleared mouse brains and yields biological insights into the vascular function of the brain.

Harmonizing brain magnetic resonance imaging methods for vascular contributions to neurodegeneration

INTRODUCTION

Many consequences of cerebrovascular disease are identifiable by magnetic resonance imaging (MRI), but variation in methods limits multicenter studies and pooling of data. The European Union Joint Program on Neurodegenerative Diseases (EU JPND) funded the HARmoNizing Brain Imaging MEthodS for VaScular Contributions to Neurodegeneration (HARNESS) initiative, with a focus on cerebral small vessel disease.

METHODS

Surveys, teleconferences, and an in-person workshop were used to identify gaps in knowledge and to develop tools for harmonizing imaging and analysis.

RESULTS

A framework for neuroimaging biomarker development was developed based on validating repeatability and reproducibility, biological principles, and feasibility of implementation. The status of current MRI biomarkers was reviewed. A website was created at www.harness-neuroimaging.org with acquisition protocols, a software database, rating scales and case report forms, and a deidentified MRI repository.

CONCLUSIONS

The HARNESS initiative provides resources to reduce variability in measurement in MRI studies of cerebral small vessel disease.

In vivo widefield calcium imaging of the mouse cortex for analysis of network connectivity in health and brain disease

The organization of brain areas in functionally connected networks, their dynamic changes, and perturbations in disease states are subject of extensive investigations. Research on functional networks in humans predominantly uses functional magnetic resonance imaging (fMRI). However, adopting fMRI and other functional imaging methods to mice, the most widely used model to study brain physiology and disease, poses major technical challenges and faces important limitations. Hence, there is great demand for alternative imaging modalities for network characterization. Here, we present a refined protocol for in vivo widefield calcium imaging of both cerebral hemispheres in mice expressing a calcium sensor in excitatory neurons. We implemented a stringent protocol for minimizing anesthesia and excluding movement artifacts which both imposed problems in previous approaches. We further adopted a method for unbiased identification of functional cortical areas using independent component analysis (ICA) on resting-state imaging data. Biological relevance of identified components was confirmed using stimulus-dependent cortical activation. To explore this novel approach in a model of focal brain injury, we induced photothrombotic lesions of the motor cortex, determined changes in inter- and intrahemispheric connectivity at multiple time points up to 56 days post-stroke and correlated them with behavioral deficits. We observed a severe loss in interhemispheric connectivity after stroke, which was partially restored in the chronic phase and associated with corresponding behavioral motor deficits. Taken together, we present an improved widefield calcium imaging tool accounting for anesthesia and movement artifacts, adopting an advanced analysis pipeline based on human fMRI algorithms and with superior sensitivity to recovery mechanisms in mouse models compared to behavioral tests. This tool will enable new studies on interhemispheric connectivity in murine models with comparability to human imaging studies for a wide spectrum of neuroscience applications in health and disease.

Decreased CSF Levels of ß-Amyloid in Patients With Cortical Superficial Siderosis

Background: Cortical superficial siderosis (cSS) represents a key neuroimaging marker of cerebral amyloid angiopathy (CAA) that is associated with intracranial hemorrhages and cognitive impairment. Nevertheless, the association between cSS and core cerebrospinal fluid (CSF) biomarkers for dementia remain unclear.

Methods: One hundred and one patients with probable (79%, 80/101) or possible (21%, 21/101) CAA according to the modified Boston criteria and mild cognitive impairment according to Petersen criteria were prospectively included between 2011 and 2016. CSF analyses of ß-amyloid 42, ß-amyloid 40, total tau and phosphorylated tau were performed using sandwich-type enzyme-linked immunosorbent-assay. All patients received MRI and Mini-Mental-State Examination (MMSE). Logistic regression analysis was used to adjust for possible confounders.

Results: cSS was present in 61% (62/101). Of those, 53% (33/62) had disseminated cSS and 47% (29/62) focal cSS. ß-amyloid 42 was lower in patients with cSS than in patients without cSS (OR 0.2; 95% CI 0.08–0.6; p = 0.0052) and lower in patients with disseminated cSS than in those with focal cSS (OR 0.02; 95% CI 0.003–0.2; p = 0.00057). Presence of cSS had no association with regard to ß-amyloid 40, total tau and phosphorylated tau.

Conclusions: Our results demonstrate that the presence and extent of cSS are associated with reduced CSF ß-amyloid 42 levels. Further studies are needed to investigate the underlying mechanisms of this association.

Zerebrale Mikroangiopathien

Zerebrale Mikroangiopathien, Erkrankungen der kleinen Gefäße (perforierende Arterien und Arteriolen, Kapillaren, Venolen) des Gehirns, sind häufige Ursachen von Schlaganfall und vaskulärer Demenz. Die häufigste Form ist alters- und hypertonieassoziiert, die genauen Pathomechanismen sind jedoch weitgehend unbekannt. Weitere relevante Formen sind die zerebrale Amyloidangiopathie und monogen vererbte Mikroangiopathien, wie bspw. CADASIL als häufigste erbliche Schlaganfallerkrankung. An klinischen Manifestationen finden sich akute (ischämischer oder hämorrhagischer Schlaganfall) und chronische Symptome. Zu letzteren zählen eine Gangstörung, affektive Symptome und eine vaskuläre kognitive Störung mit Defiziten vorwiegend im Bereich der Exekutivfunktionen. In der MRT finden sich charakteristische Gewebeläsionen, u. a. konfluierende T2-Hyperintensitäten (Leukenzephalopathie), Lakunen, Mikroblutungen und kortikale Mikroinfarkte. Zudem kommt es im Verlauf zu einer Gehirnatrophie. Differenzialdiagnostisch müssen die verschiedenen Formen der Mikroangiopathie voneinander abgegrenzt werden, da dies ggf. therapeutische Konsequenzen hat. Ferner stellen entzündliche ZNS-Erkrankungen und Leukodystrophien mögliche Differenzialdiagnosen dar. Therapeutisch steht die Optimierung des Gefäßrisikoprofils im Vordergrund.

Arterial branching and basal ganglia lacunes: A study in pure small vessel disease

Introduction

Lacunes are defined morphologically by size and location, but radiological characteristics alone may be unable to distinguish small vessel disease aetiology from alternative mechanisms. We investigated the branching order of arterial vessels associated with basal ganglia lacunes in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), in order to improve the understanding of their pathogenesis in pure cerebral small vessel disease.

Patients and methods

Adults with a confirmed diagnosis of CADASIL were included. A pilot study was conducted in a Scottish CADASIL cohort. The Paris-Munich CADASIL cohort was used for independent validation. Lacunes identified on T1-weighted magnetic resonance imaging scans were registered to a standard brain template. A microangiographic template of the basal ganglia vasculature was automatically overlaid onto coronal slices, and raters estimated the vessel branching order related to each lacune.

Results

Of 179 lacunes, 150 (84%) were associated with third-order vessels. In 14 incident lacunes, 11 (79%) were associated with third-order vessels. In the pilot study, lacune volume was significantly lower in lacunes associated with third-order vessels (0.04 ml ± 0.04 ml) compared to second-order vessels (0.48 ± 0.16 ml; p < 0.001).

Discussion

In this study of CADASIL patients, most lacunes were small and associated with third-order vessel disease. This suggests that these are the vessels primarily affected in cerebral small vessel disease. Microangiographic template techniques could be used to further investigate in a general stroke population whether finding large lacunes originating from higher order vessels indicates an alternative cause of stroke.

Conclusion

Lacunes in pure small vessel disease are associated with the smallest vessels in the basal ganglia.

METACOHORTS for the study of vascular disease and its contribution to cognitive decline and neurodegeneration: An initiative of the Joint Programme for Neurodegenerative Disease Research

Dementia is a global problem and major target for health care providers. Although up to 45% of cases are primarily or partly due to cerebrovascular disease, little is known of these mechanisms or treatments because most dementia research still focuses on pure Alzheimer's disease. An improved understanding of the vascular contributions to neurodegeneration and dementia, particularly by small vessel disease, is hampered by imprecise data, including the incidence and prevalence of symptomatic and clinically "silent" cerebrovascular disease, long-term outcomes (cognitive, stroke, or functional), and risk factors. New large collaborative studies with long follow-up are expensive and time consuming, yet substantial data to advance the field are available. In an initiative funded by the Joint Programme for Neurodegenerative Disease Research, 55 international experts surveyed and assessed available data, starting with European cohorts, to promote data sharing to advance understanding of how vascular disease affects brain structure and function, optimize methods for cerebrovascular disease in neurodegeneration research, and focus future research on gaps in knowledge. Here, we summarize the results and recommendations from this initiative. We identified data from over 90 studies, including over 660,000 participants, many being additional to neurodegeneration data initiatives. The enthusiastic response means that cohorts from North America, Australasia, and the Asia Pacific Region are included, creating a truly global, collaborative, data sharing platform, linked to major national dementia initiatives. Furthermore, the revised World Health Organization International Classification of Diseases version 11 should facilitate recognition of vascular-related brain damage by creating one category for all cerebrovascular disease presentations and thus accelerate identification of targets for dementia prevention.

Liraglutide suppresses postprandial triglyceride and apolipoprotein B48 elevations after a fat-rich meal in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled, cross-over trial

AIMS

Postprandial triglyceridaemia is a risk factor for cardiovascular disease (CVD). This study investigated the effects of steady-state liraglutide 1.8 mg versus placebo on postprandial plasma lipid concentrations after 3 weeks of treatment in patients with type 2 diabetes mellitus (T2DM).

METHODS

In a cross-over trial, patients with T2DM (n = 20, 18-75 years, BMI 18.5-40 kg/m²) were randomized to once-daily subcutaneous liraglutide (weekly dose escalation from 0.6 to 1.8 mg) and placebo. After each 3-week period, a standardized fat-rich meal was provided, and the effects of liraglutide on triglyceride (primary endpoint AUC(0-8h)), apolipoprotein B48, non-esterified fatty acids, glycaemic responses and gastric emptying were assessed. ClinicalTrials.gov ID: NCT00993304.

FUNDING

Novo Nordisk A/S.

RESULTS

After 3 weeks, mean postprandial triglyceride (AUC(0-8h) liraglutide/placebo treatment-ratio 0.72, 95% CI [0.62-0.83], p = 0.0004) and apolipoprotein B48 (AUC(0-8h) ratio 0.65 [0.58-0.73], p < 0.0001) significantly decreased with liraglutide 1.8 mg versus placebo, as did iAUC(0-8h) and C(max) (p < 0.001). No significant treatment differences were observed for non-esterified fatty acids. Mean postprandial glucose and glucagon AUC(0-8h) and C(max) were significantly reduced with liraglutide versus placebo. Postprandial gastric emptying rate [assessed by paracetamol absorption (liquid phase) and the ¹³C-octanoate breath test (solid phase)] displayed no treatment differences. Mean low-density lipoprotein and total cholesterol decreased significantly with liraglutide versus placebo.

CONCLUSIONS

Liraglutide treatment in patients with T2DM significantly reduced postprandial excursions of triglyceride and apolipoprotein B48 after a fat-rich meal, independently of gastric emptying. Results indicate liraglutide's potential to reduce CVD risk via improvement of postprandial lipaemia.

Cortical folding influences migraine aura symptoms in CADASIL

OBJECTIVE

Migraine with aura is a hallmark of cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL). In contrast with the majority of CADASIL patients, some affected subjects never experience visual symptoms during their attacks of migraine with aura. The aim of this study was to determine whether specific morphology of the primary visual cortex is associated with the absence of visual symptoms during migraine aura in CADASIL.

METHODS

Patients from a large cohort of CADASIL patients, aged <45 years, and with a modified Rankin's scale ≤1 were included in the study. Width and depth of the calcarine sulcus in the primary visual cortex as well as cortical thickness in its neighbourhood were compared between patients with visual and those with non-visual migraine auras.

RESULTS

31 patients had visual symptoms (VA group) while nine reported only non-visual symptoms (NVA group) during their migraine auras. Asymmetry index of the calcarine sulcal depth largely differed between the NVA group and the VA group (0.22±0.1 vs -0.004±0.2; p=1.7×10(-6)). The width of the right calcarine sulcus was significantly lower in the VA group (p=0.04) and cortical thickness was larger in the NVA group (p=0.03).

CONCLUSION

The absence of visual symptoms during migraine auras was associated with a profound asymmetry of the primary visual cortex. Aura symptoms seem to be linked to the morphology of the primary visual cortex in CADASIL. This finding potentially reflects more general relationships between spreading depression and cortex morphology in migraine with aura.

Effects of gender on the phenotype of CADASIL

BACKGROUND AND PURPOSE

In the general population, migraine, cerebrovascular diseases, and vascular dementia differ in many aspects between men and women. CADASIL is considered a unique model to investigate migraine with aura, stroke, and dementia related to ischemic small vessel disease. This study aims to evaluate the effect of gender on the main clinical and neuroimaging characteristics of CADASIL.

METHODS

Cross-sectional data from 313 CADASIL patients including various clinical and cognitive scores and MRI parameters were compared between men and women, and between those younger and older than the median age of the population corresponding to the usual age of menopause (51 years).

RESULTS

At younger than 51 years, migraine with aura was 50% more prevalent in women and stroke was 75% more prevalent in men. After the fifth decade, men had higher National Institutes of Health Stroke Scale and Rankin scores than women and more severe executive dysfunction, although global cognitive scores were similar. Age at first stroke, the number of stroke events, and the prevalence of dementia and psychiatric symptoms did not differ between men and women. Brain volume was lower in men with a trend for a larger volume of lacunar infarcts.

CONCLUSIONS

In CADASIL, migraine with aura is more frequent in women and stroke is more frequent in men before the age of menopause. This difference seems to vanish after this age limit but may result in a higher degree of cognitive impairment and cerebral atrophy in men at the late stage of the disease. The presumable role of ovarian hormones in these gender-related differences remains to be explored.

Weight loss with liraglutide, a once-daily human glucagon-like peptide-1 analogue for type 2 diabetes treatment as monotherapy or added to metformin, is primarily as a result of a reduction in fat tissue

AIM

The effect on body composition of liraglutide, a once-daily human glucagon-like peptide-1 analogue, as monotherapy or added to metformin was examined in patients with type 2 diabetes (T2D).

METHODS

These were randomized, double-blind, parallel-group trials of 26 [Liraglutide Effect and Action in Diabetes-2 (LEAD-2)] and 52 weeks (LEAD-3). Patients with T2D, aged 18-80 years, body mass index (BMI) < or =40 kg/m(2) (LEAD-2), < or =45 kg/m(2) (LEAD-3) and HbA1c 7.0-11.0% were included. Patients were randomized to liraglutide 1.8, 1.2 or 0.6 mg/day, placebo or glimepiride 4 mg/day, all combined with metformin 1.5-2 g/day in LEAD-2 and to liraglutide 1.8, 1.2 or glimepiride 8 mg/day in LEAD-3. LEAD-2/3: total lean body tissue, fat tissue and fat percentage were measured. LEAD-2: adipose tissue area and hepatic steatosis were assessed.

RESULTS

LEAD-2: fat percentage with liraglutide 1.2 and 1.8 mg/metformin was significantly reduced vs. glimepiride/metformin (p < 0.05) but not vs. placebo. Visceral and subcutaneous adipose tissue areas were reduced from baseline in all liraglutide/metformin arms. Except with liraglutide 0.6 mg/metformin, reductions were significantly different vs. changes seen with glimepiride (p < 0.05) but not with placebo. Liver-to-spleen attenuation ratio increased with liraglutide 1.8 mg/metformin possibly indicating reduced hepatic steatosis. LEAD-3: reductions in fat mass and fat percentage with liraglutide monotherapy were significantly different vs. increases with glimepiride (p < 0.01).

CONCLUSION

Liraglutide (monotherapy or added to metformin) significantly reduced fat mass and fat percentage vs. glimepiride in patients with T2D.

Ischemic stroke of the cortical "hand knob" area: stroke mechanisms and prognosis

Cortical ischemic stroke affecting the precentral "hand knob" area is a rare but well known stroke entity. To date, little is known about the underlying stroke mechanisms and the prognosis. Twenty-nine patients admitted to our service between 2003 and 2007 were included in the study on the basis of an acute ischemic infarct of the cortical "hand knob" area confirmed by diffusion-weighted magnetic resonance imaging with contralateral hand paresis. For all patients clinical, epidemiological as well as imaging data at the time point of admission were analysed retrospectively and follow-up data on all patients was obtained. The majority (n = 21/72%) had an isolated infarct of the cortical "hand knob" area. In 23 (79%) patients it was a first ever stroke. Ten patients (34%) had ipsilateral extracranial stenosis of the internal carotid artery (ICA), whereas potential cardiac embolic sources were less frequent (n = 4/14%). No patient exhibited ipsilateral MCA stenosis. All but two patients (93%) had marked atherosclerotic alterations of the ICA. Hypertension was the most prevalent vascular risk factor (n = 23/79%). At follow-up (mean 25.0 months, range 0.4-47.4 months) no patient had died and only one (3%) experienced a recurrent stroke. The majority of patients (79%) reported improvement of hand paresis, 17 (59%) were asymptomatic (modified Rankin score = 0). Only one patient was significantly disabled due to a recurrent stroke. In conclusion, ischemic infarcts affecting the cortical "hand knob" area are frequently associated with atherosclerotic changes of the carotid artery, suggesting an arterio-arterial thrombembolic stroke mechanism. It mostly reflects first ever ischemic stroke, and follow-up data suggest a rather benign course.

Impact on regional recurrence and survival of axillary surgery in women with node-negative primary breast cancer

Background

This study examined whether axillary lymph node dissection (ALND) with removal of many normal lymph nodes resulted in a reduced rate of axillary recurrence and better survival, as reported in recent studies.

Methods

The follow-up analyses were based on 8657 patients with node-negative primary breast cancer treated solely by surgery. Median follow-up was 9 years.

Results

The number of lymph nodes removed correlated with a reduction in the rate of subsequent axillary recurrence (from 2·1 to 0·4 per cent; P = 0·037), local recurrence (from 7·4 to 3·8 per cent; P &lt; 0·001) distant metastases (from 15·0 to 10·3 per cent; P &lt; 0·001) and death as first event (from 7·5 to 5·5 per cent; P = 0·012).

Conclusion

When ALND is indicated, at least ten axillary lymph nodes should be retrieved. The role of ALND as primary treatment has decreased significantly during the past decade. The findings leave the concept of the sentinel node biopsy intact, as a highly specific procedure compared to ALND.

Axillary staging during surgery for breast cancer

Background

Axillary lymph node status remains the single most important prognostic parameter in patients with breast cancer. In approximately half of operations sentinel lymph node biopsy cannot be employed and axillary dissection is indicated. Retrieval of ten nodes has hitherto been considered sufficient, but it remains questionable whether the removal of more lymph nodes might improve staging.

Methods

Data from 31 679 breast cancer operations in Denmark were analysed.

Results

The number of axillary lymph nodes retrieved was an independent and strong predictor of node positivity. The more lymph nodes retrieved, the better the staging of the disease; this was evident for all sizes of tumour. Dissection of 20 or more nodes rather than ten to 14 increased the probability of node positivity from 14·2 to 25·9 per cent for 1–5-mm tumours, from 38·6 to 47·9 per cent for 11–20-mm tumours, and from 80·6 to 90·0 per cent for tumours with diameter greater than 50 mm.

Conclusion

The number of metastatic lymph nodes increased as more nodes were retrieved. These findings underline the need for high-quality specialist surgical and pathological services in breast cancer treatment.

The relation between socioeconomic and demographic factors and tumour stage in women diagnosed with breast cancer in Denmark, 1983-1999

The authors investigated the association between socioeconomic position and stage of breast cancer at the time of diagnosis in a nationwide Danish study. All 28 765 women with a primary invasive breast cancer diagnosed between 1983 and 1999 were identified in a nationwide clinical database and information on socioeconomic variables was obtained from Statistics Denmark. The risk of being diagnosed with a high-risk breast cancer, that is size >20 mm, lymph-node positive, ductal histology/high histologic grade and hormone receptor negative, was analysed by multivariate logistic regression. The adjusted odds ratio (OR) for high-risk breast cancer was reduced with longer education with a 12% reduced risk (95% confidence interval (CI), 0.80,0.96) in women with higher education and increased with reduced disposable income (low income group: OR, 1.22; 95% CI, 1.10,1.34). There was an urban–rural gradient, with higher risk among rural women (OR 1.10; 95 % CI, 1.02, 1.18) and lower risk among women in the capital suburbs (OR, 0.85; 95% CI, 0.78, 0.93) and capital area (OR, 0.93; 95% CI, 0.84–1.02). These factors were significant only for postmenopausal women, although similar patterns were observed among the premenopausal women, suggesting a subgroup of aggressive premenopausal breast cancers less influenced by socioeconomic factors.

Does timing of adjuvant chemotherapy influence the prognosis after early breast cancer? Results of the Danish Breast Cancer Cooperative Group (DBCG)

The purpose of this study was to examine the effect on survival of delaying the start of adjuvant chemotherapy for early breast cancer for up to 3 months after surgery. In the nation-wide clinical trials of the Danish Breast Cancer Cooperative Group, 7501 breast cancer patients received chemotherapy within 3 months of surgery between 1977 and 1999: 352 with classical cyclofosfamide, metotrexate and 5-fluorouracil (CMF); 6065 with CMF i.v. and 1084 with cyclofosfamide, epirubicin and 5-fluorouracil. For the analysis, the time between surgery and the start of chemotherapy was divided into four strata (1–3, 4, 5 and 6–13 weeks). The results show that within the three groups of chemotherapy, there was an even distribution of known prognostic factors across the four strata of initiation of chemotherapy. There was no pattern indicating a benefit from early start of chemotherapy. No significant interactions were found for subgroups of patients with a poorer prognosis (many involved lymph nodes, high-grade malignancies or hormone receptor negative disease). In conclusion, we have found no evidence for a survival benefit due to early initiation of adjuvant chemotherapy within the first 2–3 months after surgery.

[Morphological results after an experimental transplantation of autogenous cancellous bone in dogs (author's transl)]

Cell activity during the period of healing of an autogenous cancellous graft inserted into an artificial continuity defect of the ulna was studied in 20 adult dogs by light microscopy using the semithin sectioning technique. The defects were stabilised by osteosynthesis using metal plates and screws. The animals were divided into 4 groups and the autografts were investigated 1, 2, 4 and 8 weeks after transplantation. Histologic analysis showed, that ... 1. one week after transplantation, undifferentiated cells resembling reticular cells, haemocytoblasts and many closely packed osteoblasts were scattered among the trabecular network of the autogenous cancellous graft. The survival of transplanted cells in our opinion is evident, by the absence of any sign of cell death or macrophage activity. 2. two to 4 weeks after transplantation a remarkable increase of the osteoblast activity was noted. This osteogenic cell activity was mainly directed toward bone formation along the surface of contact of the autograft with the adjoining bone and there was more than one layer of osteoblasts and osteoid. Osteoblasts were also found lying along the trabecular surface of transplanted cancellous bone, but here they were arranged in a layer, which was usually only one cell deep. 3. eight weeks after transplantation there was a remarkable change in the appearance of the autogenous cancellous graft. The activity of the multinucleated osteoclasts was significantly increased in the direction of the surface of contact of the autograft with the compact receptor bone. Evidently the osteoclasts produce the prior conditions for a closer contact of the autogenous cancellous graft with the adjoining compact bone.

[Proximal rupture in the triceps surae a typical, but often unrecognized injury]

An account is given of 12 high ruptures of the triceps surae, a traumatic lesion of the medial belly of the gastrocnemius, caused by sudden overstreching of the muscle by concomitant ankle dorsiflexion and full knee extension. In all cases the authors found characteristic clinical features. Surgical exploration in 5 of 12 cases verified the ruptures of the musculotendinous junction of the medial gastrocnemius belly. A follow-up study of 2 years showed that the surgical treatment seems to be better, especially in younger and athletic patients.