Identification of corneal and intra-epidermal axonal swellings in amyotrophic lateral sclerosis

INTRODUCTION/AIMS

In patients with amyotrophic lateral sclerosis (ALS), axonal spheroids in motor axons have been identified in post-mortem studies. In this study, axonal spheroids and swellings on C-fibers of ALS patients were investigated using corneal confocal microscopy (CCM) and skin biopsy, respectively.

METHODS

Thirty-one ALS patients and 20 healthy subjects were evaluated with CCM to assess corneal nerve-fiber length (CNFL), -fiber density (CNFD), -branch density (CNBD), dendritic cell (DC) density, and axonal spheroids originating from C-fibers (>100 μm2 ). In addition, intraepidermal nerve fiber density (IENFD) and axonal swellings (>1.5 μm) were assessed in skin biopsies obtained from the arms and legs of 22 patients and 17 controls.

RESULTS

In ALS patients, IENFD, CNFD, CNFL, and CNBD were not different from controls. The density of DCs and the number of patients with increased DC density were higher in ALS patients than controls (p = .0005 and p = .008). The number of patients with axonal spheroids was higher than controls (p = .03).

DISCUSSION

Evaluation of DCs and axonal bulbs in C-fibers of ALS patients could provide insights into pathophysiology or potentially serve as biomarkers in ALS.

Structural changes in Schwann cells and nerve fibres in type 1 diabetes: relationship with diabetic polyneuropathy

AIMS/HYPOTHESIS

Our aim was to investigate structural changes of cutaneous Schwann cells (SCs), including nociceptive Schwann cells (nSCs) and axons, in individuals with diabetic polyneuropathy. We also aimed to investigate the relationship between these changes and peripheral neuropathic symptoms in type 1 diabetes.

METHODS

Skin biopsies (3 mm) taken from carefully phenotyped participants with type 1 diabetes without polyneuropathy (T1D, n=25), type 1 diabetes with painless diabetic polyneuropathy (T1DPN, n=30) and type 1 diabetes with painful diabetic polyneuropathy (P-T1DPN, n=27), and from healthy control individuals (n=25) were immunostained with relevant antibodies to visualise SCs and nerve fibres. Stereological methods were used to quantify the expression of cutaneous SCs and nerve fibres.

RESULTS

There was a difference in the number density of nSCs not abutting to nerve fibres between the groups (p=0.004) but not in the number density of nSCs abutting to nerve fibres, nor in solitary or total subepidermal SC soma number density. The overall dermal SC expression (measured by dermal SC area fraction and subepidermal SC process density) and peripheral nerve fibre expression (measured by intraepidermal nerve fibre density, dermal nerve fibre area fraction and subepidermal nerve fibre density) differed between the groups (all p<0.05): significant differences were seen in participants with T1DPN and P-T1DPN compared with those without diabetic polyneuropathy (healthy control and T1D groups) (all p<0.05). No difference was found between participants in the T1DPN and P-T1DPN group, nor between participants in the T1D and healthy control group (all p>0.05). Correlational analysis showed that cutaneous SC processes and nerve fibres were highly associated, and they were weakly negatively correlated with different neuropathy measures.

CONCLUSIONS/INTERPRETATION

Cutaneous SC processes and nerves, but not SC soma, are degenerated and interdependent in individuals with diabetic polyneuropathy. However, an increase in structurally damaged nSCs was seen in individuals with diabetic polyneuropathy. Furthermore, dermal SC processes and nerve fibres correlate weakly with clinical measures of neuropathy and may play a partial role in the pathophysiology of diabetic polyneuropathy in type 1 diabetes.

Structural Changes of Cutaneous Immune Cells in Patients With Type 1 Diabetes and Their Relationship With Diabetic Polyneuropathy

BACKGROUND AND OBJECTIVES

Diabetic polyneuropathy (DPN) is a complication of diabetes characterized by pain or lack of peripheral sensation, but the underlying mechanisms are not yet fully understood. Recent evidence showed increased cutaneous macrophage infiltration in patients with type 2 diabetes and painful DPN, and this study aimed to understand whether the same applies to type 1 diabetes.

METHODS

The study included 104 participants: 26 healthy controls and 78 participants with type 1 diabetes (participants without DPN [n = 24], participants with painless DPN [n = 29], and participants with painful DPN [n = 25]). Two immune cells, dermal IBA1⁺ macrophages and epidermal Langerhans cells (LCs, CD207⁺), were visualized and quantified using immunohistological labeling and stereological counting methods on skin biopsies from the participants. The IBA1⁺ macrophage infiltration, LC number density, LC soma cross-sectional area, and LC processes were measured in this study.

RESULTS

Significant difference in IBA1⁺ macrophage expression was seen between the groups (p = 0.003), with lower expression of IBA1 in participants with DPN. No differences in LC morphologies (LC number density, soma cross-sectional area, and process level) were found between the groups (all p > 0.05). In addition, IBA1⁺ macrophages, but not LCs, correlated with intraepidermal nerve fiber density, Michigan neuropathy symptom inventory, (questionnaire and total score), severity of neuropathy as assessed by the Toronto clinical neuropathy score, and vibration detection threshold in the whole study cohort.

DISCUSSION

This study showed expressional differences of cutaneous IBA1⁺ macrophages but not LC in participants with type 1 diabetes-induced DPN compared with those in controls. The study suggests that a reduction in macrophages may play a role in the development and progression of autoimmune-induced diabetic neuropathy.

Joint European Academy of Neurology-European Pain Federation-Neuropathic Pain Special Interest Group of the International Association for the Study of Pain guidelines on neuropathic pain assessment

BACKGROUND AND PURPOSE

In these guidelines, we aimed to develop evidence-based recommendations for the use of screening questionnaires and diagnostic tests in patients with neuropathic pain (NeP).

METHODS

We systematically reviewed studies providing information on the sensitivity and specificity of screening questionnaires, and quantitative sensory testing, neurophysiology, skin biopsy, and corneal confocal microscopy. We also analysed how functional neuroimaging, peripheral nerve blocks, and genetic testing might provide useful information in diagnosing NeP.

RESULTS

Of the screening questionnaires, Douleur Neuropathique en 4 Questions (DN4), I-DN4 (self-administered DN4), and Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) received a strong recommendation, and S-LANSS (self-administered LANSS) and PainDETECT weak recommendations for their use in the diagnostic pathway for patients with possible NeP. We devised a strong recommendation for the use of skin biopsy and a weak recommendation for quantitative sensory testing and nociceptive evoked potentials in the NeP diagnosis. Trigeminal reflex testing received a strong recommendation in diagnosing secondary trigeminal neuralgia. Although many studies support the usefulness of corneal confocal microscopy in diagnosing peripheral neuropathy, no study specifically investigated the diagnostic accuracy of this technique in patients with NeP. Functional neuroimaging and peripheral nerve blocks are helpful in disclosing pathophysiology and/or predicting outcomes, but current literature does not support their use for diagnosing NeP. Genetic testing may be considered at specialist centres, in selected cases.

CONCLUSIONS

These recommendations provide evidence-based clinical practice guidelines for NeP diagnosis. Due to the poor-to-moderate quality of evidence identified by this review, future large-scale, well-designed, multicentre studies assessing the accuracy of diagnostic tests for NeP are needed.

Assessing Corneal Confocal Microscopy and Other Small Fiber Measures in Diabetic Polyneuropathy

BACKGROUND AND OBJECTIVES

Damage to small nerve fibers is common in diabetic polyneuropathy (DPN), and the diagnosis of DPN relies on subjective symptoms and signs in a combination with objective confirmatory tests, typically electrophysiology or intraepidermal nerve fiber density (IENFD) from skin biopsy. Corneal confocal microscopy (CCM) has been introduced as a tool to detect DPN. However, it is unclear if CCM can reliably be used to diagnose DPN and how the technique compares with other commonly used measures of small fiber damage, such as IENFD, cold detection threshold (CDT), and warm detection threshold (WDT). Therefore, we assessed and compared the use of CCM, IENFD, CDT, and WDT in the diagnosis of DPN in patients with type 2 diabetes.

METHODS

In this cohort study, the participants underwent detailed neurologic examination, electrophysiology, quantification of IENFD, CCM, and quantitative sensory testing. Definition of DPN was made in accordance with the Toronto criteria for diabetic neuropathy (without relying on IENFD and thermal thresholds).

RESULTS

A total of 214 patients with at least probable DPN, 63 patients without DPN, and 97 controls without diabetes were included. Patients with DPN had lower CCM measures (corneal nerve fiber length [CNFL], nerve fiber density, and branch density), IENFD, CDT, and WDT compared with patients without DPN (p ≤ 0.001, <0.001, 0.002, p < 0.001, p = 0.003, and <0.005, respectively), whereas there was no difference between controls and patients with diabetes without DPN. All 3 CCM measures showed a very low diagnostic sensitivity with CNFL showing the highest (14.4% [95% CI 9.8-18.4]) and a specificity of 95.7% (88.0-99.1). In comparison, the sensitivity of abnormal CDT and/or WDT was 30.5% (24.4-37.0) with a specificity of 84.9% (74.6-92.2). The sensitivity of abnormal IENFD was highest among all measures with a value of 51.1% (43.7-58.5) and a specificity of 90% (79.5-96.2). CCM measures did not correlate with IENFD, CDT/WDT, or neuropathy severity in the group of patients with DPN.

DISCUSSION

CCM measures showed the lowest sensitivity compared with other small fiber measures in the diagnosis of DPN. This indicates that CCM is not a sensitive method to detect DPN in recently diagnosed type 2 diabetes.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that CCM measures aid in the detection of DPN in recently diagnosed type 2 diabetics but with a low sensitivity when compared with other small fiber measures.

Genomic characterisation of hormone receptor-positive breast cancer arising in very young women

BACKGROUND

Very young premenopausal women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+HER2-) early breast cancer (EBC) have higher rates of recurrence and death for reasons that remain largely unexplained.

PATIENTS AND METHODS

Genomic sequencing was applied to HR+HER2- tumours from patients enrolled in the Suppression of Ovarian Function Trial (SOFT) to determine genomic drivers that are enriched in young premenopausal women. Genomic alterations were characterised using next-generation sequencing from a subset of 1276 patients (deep targeted sequencing, n = 1258; whole-exome sequencing in a young-age, case-control subsample, n = 82). We defined copy number (CN) subgroups and assessed for features suggestive of homologous recombination deficiency (HRD). Genomic alteration frequencies were compared between young premenopausal women (<40 years) and older premenopausal women (≥40 years), and assessed for associations with distant recurrence-free interval (DRFI) and overall survival (OS).

RESULTS

Younger women (<40 years, n = 359) compared with older women (≥40 years, n = 917) had significantly higher frequencies of mutations in GATA3 (19% versus 16%) and CN amplifications (CNAs) (47% versus 26%), but significantly lower frequencies of mutations in PIK3CA (32% versus 47%), CDH1 (3% versus 9%), and MAP3K1 (7% versus 12%). Additionally, they had significantly higher frequencies of features suggestive of HRD (27% versus 21%) and a higher proportion of PIK3CA mutations with concurrent CNAs (23% versus 11%). Genomic features suggestive of HRD, PIK3CA mutations with CNAs, and CNAs were associated with significantly worse DRFI and OS compared with those without these features. These poor prognostic features were enriched in younger patients: present in 72% of patients aged <35 years, 54% aged 35-39 years, and 40% aged ≥40 years. Poor prognostic features [n = 584 (46%)] versus none [n = 692 (54%)] had an 8-year DRFI of 84% versus 94% and OS of 88% versus 96%. Younger women (<40 years) had the poorest outcomes: 8-year DRFI 74% versus 85% and OS 80% versus 93%, respectively.

CONCLUSION

These results provide insights into genomic alterations that are enriched in young women with HR+HER2- EBC, provide rationale for genomic subgrouping, and highlight priority molecular targets for future clinical trials.

Stereological and electrophysiological evaluation of autonomic involvement in amyotrophic lateral sclerosis

OBJECTIVE

Previous studies have identified autonomic dysfunction in amyotrophic lateral sclerosis (ALS) using mostly neurophysiological techniques. In this study, stereological evaluation of autonomic fibers and sweat glands has been performed to identify structural evidence of autonomic denervation in patients with ALS.

METHODS

In this study, 29 ALS patients were compared to 29 controls using COMPASS-31 questionnaire, sympathetic skin response (SSR), and heart rate variability (HRV) at rest. From the same cohorts, 20 ALS patients and 15 controls were further evaluated using staining of autonomic nerve fibers and sweat glands in skin biopsies. SSR and resting HRV were repeated in the ALS patient cohort one year later.

RESULTS

COMPASS-31 total score, gastrointestinal- and urinary-sub scores were higher in ALS patients than controls (P = 0.004, P = 0.005, and P = 0.049, respectively). In the ALS patient cohort, SSR amplitudes in hands and feet were lower than in controls (P<0.0001 and P = 0.0009, respectively), but there was no difference in resting HRV (P>0.05). While there was no change in nerve fibers innervating sweat glands, their density was lower in ALS patients than controls, and semi-quantitative analysis also showed structural damage (P = 0.02 and P = 0.001, respectively). SSR and resting HRV of ALS patients remained stable during the one-year follow-up period (P>0.05).

DISCUSSION

Supporting abnormal neurophysiological tests, stereological analysis revealed direct evidence of autonomic denervation in ALS patients. However, the degenerative process in autonomic nerve fibers is relatively slow, compared to the rate of motor neuron degeneration in this condition.

Effects of progressive resistance training in individuals with type 2 diabetic polyneuropathy: a randomised assessor-blinded controlled trial

AIMS/HYPOTHESIS

The aim of this study was to evaluate the effects of progressive resistance training (PRT) on muscle strength, intraepidermal nerve fibre density (IENFD) and motor function in individuals with type 2 diabetic polyneuropathy (DPN) and to compare potential adaptations to those of individuals with type 2 diabetes without DPN and healthy controls.

METHODS

This was an assessor-blinded trial conducted at the Neurology department, Aarhus University Hospital. Adults with type 2 diabetes, with and without DPN and healthy control participants were randomised to either supervised PRT or non-PRT for 12 weeks. Allocation was concealed by a central office unrelated to the study. The co-primary outcomes were muscle strength in terms of the peak torque of the knee and ankle extensors and flexors, and IENFD. Secondary outcome measures included the 6 min walk test (6MWT), five-time sit-to-stand test (FTSST) and postural stability index obtained by static posturography.

RESULTS

A total of 109 individuals were enrolled in three groups (type 2 diabetes with DPN [n = 42], type 2 diabetes without DPN [n = 32] and healthy control [n = 35]). PRT resulted in muscle strength gains of the knee extensors and flexors in all three groups using comparative analysis (DPN group, PRT 10.3 ± 9.6 Nm vs non-PRT -0.4 ± 8.2 Nm; non-DPN group, PRT 7.5 ± 5.8 Nm vs non-PRT 0.6 ± 8.8 Nm; healthy control group, PRT 6.3 ± 9.0 Nm vs non-PRT -0.4 ± 8.4 Nm; p<0.05, respectively). Following PRT the DPN group improved the 6MWT (PRT 34.6 ± 40.9 m vs non-PRT 2.7 ± 19.6 m; p=0.001) and the FTSST (PRT -1.5 ± 2.2 s vs non-PRT 1.5 ± 4.6 s; p=0.02). There was no change in IENFD following PRT in any of the groups.

CONCLUSIONS/INTERPRETATION

PRT improved muscle strength of the knee extensors and flexors and motor function in individuals with type 2 diabetic polyneuropathy at levels comparable with those seen in individuals with diabetes without DPN and healthy control individuals, while no effects were observed in IENFD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03252132 FUNDING: Research reported in this paper is part of the International Diabetic Neuropathy Consortium (IDNC) research programme, supported by a Novo Nordisk Foundation Challenge Program grant (grant no. NNF14OC0011633) and Aarhus University.

Comparison of diabetic and idiopathic sensory polyneuropathies with respect to nerve fibre affection and risk factors

Background and purpose

Chronic distal sensory or sensorimotor polyneuropathy is the most common pattern of polyneuropathy. The cause of this pattern is most often diabetes or unknown. This cross-sectional study is one of the first studies to compare the demographics, cardiovascular risk factors and clinical characteristics of diabetic polyneuropathy (DPN) with idiopathic polyneuropathy (IPN).

Methods

Patients with DPN were included from a sample of 389 patients with type 2 diabetes mellitus (T2DM) enrolled from a national cohort of patients with recently diagnosed T2DM (Danish Centre for Strategic Research in Type 2 Diabetes cohort). Patients with IPN were included from a regional cohort of patients with symptoms of polyneuropathy referred for workup at a combined secondary and tertiary neurological centre (database cohort).

Results

A total of 214 patients with DPN were compared with a total of 88 patients with IPN. Patients with DPN were older (67.4 vs 59 years) and had a longer duration of neuropathy symptoms. Patients with DPN had greater body mass index (32 vs 27.4 kg/m²) and waist circumference (110 cm vs 97 cm); higher frequency of hypertension diagnosis (72.9% vs 30.7%); lower total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol levels; and a higher prevalence of use of statins (81.8% vs 19.3%). DPN was associated with a slightly higher autonomic score and total score on the Neuropathy Symptom Score; lower frequency of hyperalgesia, allodynia and decreased vibration on quantitative sensory testing; lower intraepidermal nerve fibre density count and higher frequency of small-fibre neuropathy.

Conclusion

DPN and IPN showed clear differences in neuropathy characteristics, indicating that these two entities are to be regarded as aetiologically and pathogenetically distinct.

Analysis of Macrophages and Peptidergic Fibers in the Skin of Patients With Painful Diabetic Polyneuropathy

BACKGROUND AND OBJECTIVES

The mechanisms of pain in patients with diabetic polyneuropathy are unknown. Studies have suggested a role of inflammation and increased neuropeptides peripherally in pain generation. This study examined the possible skin markers of painful diabetic polyneuropathy (P-DPN): macrophages, substance P (SP), and calcitonin gene-related peptide (CGRP).

METHODS

The participants were included from a large Danish cross-sectional clinical study of type 2 diabetes. We diagnosed definite diabetic polyneuropathy using the Toronto criteria and used the Neuropathic Pain Special Interest Group classification for defining P-DPN. We included 60 skin biopsies from patients with diabetic polyneuropathy-30 with P-DPN and 30 with nonpainful diabetic polyneuropathy (NP-DPN)-and 30 biopsies from healthy controls of similar age and sex. The biopsies were stained using PGP 9.5, IbA1, and SP and CGRP primary markers.

RESULTS

There was increased macrophage density in patients with P-DPN (8.0%) compared with that in patients with NP-DPN (5.1%, p < 0.001), and there was increased macrophage density in patients with NP-DPN (5.1%) compared with that in healthy controls (3.1%, p < 0.001). When controlling for neuropathy severity, body mass index, age, and sex, there was still a difference in macrophage density between patients with P-DPN and patients with NP-DPN. Patients with P-DPN had higher median nerve fiber length density (274.5 and 155 mm^-2 for SP and CGRP, respectively) compared with patients with NP-DPN (176 and 121 mm^-2 for SP and CGRP, respectively, p = 0.009 and 0.04) and healthy controls (185.5 and 121.5 mm^-2 for SP and CGRP, respectively), whereas there was no difference between patients with NP-DPN and controls without diabetes (p = 0.64 and 0.49, respectively). The difference between P-DPN and NP-DPN for SP and CGRP was significant only in female patients, although a trend was seen in male patients.

DISCUSSION

The findings point to a possible involvement of the innate immune system in the pathogenesis of neuropathic pain in patients with DPN, although markers of activated macrophages were not measured in this study.

Accuracy of estimating left ventricular ejection fraction in clinical routine. A SWEDEHEART registry validation study

Objective

Patients admitted to Swedish hospitals with myocardial infarction (MI) are reported to the nationwide Swedish registry for MI (SWEDEHEART). During hospital stay an echocardiography is routinely performed, and left ventricular ejection fraction (LVEF) is assessed according to the clinical praxis. LVEF is categorized as normal (&gt;50%) or mild, moderate or severely impaired (40–49%, 30–39% and &lt;30%, respectively) and reported to the registry by the treating center. The purpose of this study was to validate the reported LVEF assessments against independent echocardiography re-evaluation as this has never previously been done.

Methods

A random sample of 130 patient from three different hospitals were included. LVEF re-evaluation was performed by two independent reviewers using the modified biplane Simpson method and their mean LVEF was compared to the SWEDEHEART LVEF. Agreement between reported and re-evaluated LVEF was assessed using Gwet's AC2 statistics.

Results

Analysis showed good agreement between reported and reevaluated LVEF (AC2: 0.76 [95% CI 0.69–0.84]). The LVEF re-evaluations corresponded with registry reported categorized LVEF in 66.0% of cases. In 25.4% of cases the SWEDEHEART LVEF was lower than re-evaluated LVEF. The opposite relation was found in 8.6% of cases (p&lt;0.005).

Conclusion

Independent validation of SWEDEHEART-reported LVEF shows an overall good agreement with the re-evaluated LVEF. However, a tendency to underestimation of LVEF was observed in patients with impaired LV systolic function, in whom the reported assessment of LVEF should be interpreted more cautiously.

Funding Acknowledgement

Type of funding sources: Foundation. Main funding source(s): Selanders Stiftelse

Continuous versus intermittent extended adjuvant letrozole for breast cancer: final results of randomized phase III SOLE (Study of Letrozole Extension) and SOLE Estrogen Substudy

BACKGROUND

Late recurrences in postmenopausal women with hormone receptor-positive breast cancers remain an important challenge. Avoidance or delayed development of resistance represents the main objective in extended endocrine therapy (ET). In animal models, resistance was reversed with restoration of circulating estrogen levels during interruption of letrozole treatment. This phase III, randomized, open-label Study of Letrozole Extension (SOLE) studied the effect of extended intermittent letrozole treatment in comparison with continuous letrozole. In parallel, the SOLE estrogen substudy (SOLE-EST) analyzed the levels of estrogen during the interruption of treatment.

PATIENTS AND METHODS

SOLE enrolled 4884 postmenopausal women with hormone receptor-positive, lymph node-positive, operable breast cancer between December 2007 and October 2012 and among them, 104 patients were enrolled in SOLE-EST. They must have undergone local treatment and have completed 4-6 years of adjuvant ET. Patients were randomized between continuous letrozole (2.5 mg/day orally for 5 years) and intermittent letrozole treatment (2.5 mg/day for 9 months followed by a 3-month interruption in years 1-4 and then 2.5 mg/day during all of year 5).

RESULTS

Intention-to-treat population included 4851 women in SOLE (n = 2425 in the intermittent and n = 2426 in the continuous letrozole groups) and 103 women in SOLE-EST (n = 78 in the intermittent and n = 25 in the continuous letrozole groups). After a median follow-up of 84 months, 7-year disease-free survival (DFS) was 81.4% in the intermittent group and 81.5% in the continuous group (hazard ratio: 1.03, 95% confidence interval: 0.91-1.17). Reported adverse events were similar in both groups. Circulating estrogen recovery was demonstrated within 6 weeks after the stop of letrozole treatment.

CONCLUSIONS

Extended adjuvant ET by intermittent administration of letrozole did not improve DFS compared with continuous use, despite the recovery of circulating estrogen levels. The similar DFS coupled with previously reported quality-of-life advantages suggest intermittent extended treatment is a valid option for patients who require or prefer a treatment interruption.

Myopathic changes in patients with long-term fatigue after COVID-19

Objective

To investigate the peripheral nerve and muscle function electrophysiologically in patients with persistent neuromuscular symptoms following Coronavirus disease 2019 (COVID-19).

Methods

Twenty consecutive patients from a Long-term COVID-19 Clinic referred to electrophysiological examination with the suspicion of mono- or polyneuropathy were included. Examinations were performed from 77 to 255 (median: 216) days after acute COVID-19. None of the patients had received treatment at the intensive care unit. Of these, 10 patients were not even hospitalized. Conventional nerve conduction studies (NCS) and quantitative electromyography (qEMG) findings from three muscles were compared with 20 age- and sex-matched healthy controls.

Results

qEMG showed myopathic changes in one or more muscles in 11 patients (55%). Motor unit potential duration was shorter in patients compared to healthy controls in biceps brachii (10.02 ± 0.28 vs 11.75 ± 0.21), vastus medialis (10.86 ± 0.37 vs 12.52 ± 0.19) and anterior tibial (11.76 ± 0.31 vs 13.26 ± 0.21) muscles. All patients with myopathic qEMG reported about physical fatigue and 8 patients about myalgia while 3 patients without myopathic changes complained about physical fatigue.

Conclusions

Long-term COVID-19 does not cause large fibre neuropathy, but myopathic changes are seen.

Significance

Myopathy may be an important cause of physical fatigue in long-term COVID-19 even in non-hospitalized patients.

Axonal swellings are related to type 2 diabetes, but not to distal diabetic sensorimotor polyneuropathy

AIMS/HYPOTHESIS

Distal diabetic sensorimotor polyneuropathy (DSP) is a common complication of diabetes with many patients showing a reduction of intraepidermal nerve fibre density (IENFD) from skin biopsy, a validated and sensitive diagnostic tool for the assessment of DSP. Axonal swelling ratio is a morphological quantification altered in DSP. It is, however, unclear if axonal swellings are related to diabetes or DSP. The aim of this study was to investigate how axonal swellings in cutaneous nerve fibres are related to type 2 diabetes mellitus, DSP and neuropathic pain in a well-defined cohort of patients diagnosed with type 2 diabetes.

METHODS

A total of 249 participants, from the Pain in Neuropathy Study (UK) and the International Diabetic Neuropathy Consortium (Denmark), underwent a structured neurological examination, nerve conduction studies, quantitative sensory testing and skin biopsy. The study included four groups: healthy control study participants without diabetes (n = 45); participants with type 2 diabetes without DSP (DSP-; n = 31); and participants with evidence of DSP (DSP+; n = 173); the last were further separated into painless DSP+ (n = 74) and painful DSP+ (n = 99). Axonal swellings were defined as enlargements on epidermal-penetrating fibres exceeding 1.5 μm in diameter. Axonal swelling ratio is calculated by dividing the number of axonal swellings by the number of intraepidermal nerve fibres.

RESULTS

Median (IQR) IENFD (fibres/mm) was: 6.7 (5.2-9.2) for healthy control participants; 6.2 (4.4-7.3) for DSP-; 1.3 (0.5-2.2) for painless DSP+; and 0.84 (0.4-1.6) for painful DSP+. Swelling ratios were calculated for all participants and those with IENFD > 1.0 fibre/mm. When only those participants with IENFD > 1.0 fibre/mm were included, the axonal swelling ratio was higher in participants with type 2 diabetes when compared with healthy control participants (p < 0.001); however, there was no difference between DSP- and painless DSP+ participants, or between painless DSP+ and painful DSP+ participants. The axonal swelling ratio correlated weakly with HbA_1c (r = 0.16, p = 0.04), but did not correlate with the Toronto Clinical Scoring System (surrogate measure of DSP severity), BMI or type 2 diabetes duration.

CONCLUSIONS/INTERPRETATION

In individuals with type 2 diabetes where IENFD is >1.0 fibre/mm, axonal swelling ratio is related to type 2 diabetes but is not related to DSP or painful DSP. Axonal swellings may be an early marker of sensory nerve injury in type 2 diabetes.

Painful and non-painful diabetic neuropathy, diagnostic challenges and implications for future management

Peripheral neuropathy is one of the most common complications of both type 1 and type 2 diabetes. Up to half of patients with diabetes develop neuropathy during the course of their disease, which is accompanied by neuropathic pain in 30-40% of cases. Peripheral nerve injury in diabetes can manifest as progressive distal symmetric polyneuropathy, autonomic neuropathy, radiculo-plexopathies, and mononeuropathies. The most common diabetic neuropathy is distal symmetric polyneuropathy, which we will refer to as DN, with its characteristic glove and stocking like presentation of distal sensory or motor function loss. DN or its painful counterpart, painful DN, are associated with increased mortality and morbidity; thus, early recognition and preventive measures are essential. Nevertheless, it is not easy to diagnose DN or painful DN, particularly in patients with early and mild neuropathy, and there is currently no single established diagnostic gold standard. The most common diagnostic approach in research is a hierarchical system, which combines symptoms, signs, and a series of confirmatory tests. The general lack of long-term prospective studies has limited the evaluation of the sensitivity and specificity of new morphometric and neurophysiological techniques. Thus, the best paradigm for screening DN and painful DN both in research and in clinical practice remains uncertain. Herein, we review the diagnostic challenges from both clinical and research perspectives and their implications for managing patients with DN. There is no established DN treatment, apart from improved glycaemic control, which is more effective in type 1 than in type 2 diabetes, and only symptomatic management is available for painful DN. Currently, less than one-third of patients with painful DN derive sufficient pain relief with existing pharmacotherapies. A more precise and distinct sensory profile from patients with DN and painful DN may help identify responsive patients to one treatment versus another. Detailed sensory profiles will lead to tailored treatment for patient subgroups with painful DN by matching to novel or established DN pathomechanisms and also for improved clinical trials stratification. Large randomized clinical trials are needed to identify the interventions, i.e. pharmacological, physical, cognitive, educational, etc., which lead to the best therapeutic outcomes.

Increased peptidergic fibers as a potential cutaneous marker of pain in diabetic small fiber neuropathy

ABSTRACT

Diabetic polyneuropathy (DPN) is a common complication of diabetes and is often associated with neuropathic pain. The mechanisms underlying development and maintenance of painful DPN are largely unknown, and quantification of intraepidermal nerve fiber density from skin biopsy, one of the neuropathological gold standard when diagnosing DPN, does not differentiate between patients with and without pain. Identification of possible pain pathophysiological biomarkers in patients with painful DPN may increase our knowledge of mechanisms behind neuropathic pain. Animal models of painful DPN have been shown to have an increased density of peptidergic nerve fibers (substance P and calcitonin gene-related peptide). In this study, we performed a detailed skin biopsy analysis in a well-characterized group of DPN patients with primarily small fiber involvement, with and without pain, and in healthy controls and test for correlation between skin biopsy findings and pain intensity and quantitative sensory testing. We found that although there was no difference in intraepidermal nerve fiber density using protein gene product 9.5 between patients with and without pain, patients with pain had increased density of dermal peptidergic fibers containing substance P and calcitonin gene-related peptide compared with patients with painless DPN and healthy controls. Peptidergic nerve fiber density correlated with pain ratings in patients with pain (R = 0.33; P = 0.019), but not with quantitative sensory testing results. In this article, we show, for the first time in humans, an increased density of dermal peptidergic fibers in painful DPN. These findings provide new insight in the pathophysiological mechanisms of pain in diabetes and open the research towards new therapeutic targets.

Molecular and cellular correlates of human nerve regeneration: ADCYAP1/PACAP enhance nerve outgrowth

We only have a rudimentary understanding of the molecular and cellular determinants of nerve regeneration and neuropathic pain in humans. This cohort study uses the most common entrapment neuropathy (carpal tunnel syndrome) as a human model system to prospectively evaluate the cellular and molecular correlates of neural regeneration and its relationship with clinical recovery. In 60 patients undergoing carpal tunnel surgery [36 female, mean age 62.5 (standard deviation 12.2) years], we used quantitative sensory testing and nerve conduction studies to evaluate the function of large and small fibres before and 6 months after surgery. Clinical recovery was assessed with the global rating of change scale and Boston Carpal Tunnel Questionnaire. Twenty healthy participants provided normative data [14 female, mean age 58.0 (standard deviation 12.9) years]. At 6 months post-surgery, we noted significant recovery of median nerve neurophysiological parameters (P < 0.0001) and improvements in quantitative sensory testing measures of both small and large nerve fibre function (P < 0.002). Serial biopsies revealed a partial recovery of intraepidermal nerve fibre density [fibres/mm epidermis pre: 4.20 (2.83), post: 5.35 (3.34), P = 0.001], whose extent correlated with symptom improvement (r = 0.389, P = 0.001). In myelinated afferents, nodal length increased postoperatively [pre: 2.03 (0.82), post: 3.03 (1.23), P < 0.0001] suggesting that this is an adaptive phenomenon. Transcriptional profiling of the skin revealed 31 differentially expressed genes following decompression, with ADCYAP1 (encoding pituitary adenylate cyclase activating peptide, PACAP) being the most strongly upregulated (log2 fold-change 1.87, P = 0.0001) and its expression was associated with recovery of intraepidermal nerve fibres. We found that human induced pluripotent stem cell-derived sensory neurons expressed the receptor for PACAP and that this peptide could significantly enhance axon outgrowth in a dose-dependent manner in vitro [neurite length PACAP 1065.0 µm (285.5), vehicle 570.9 μm (181.8), P = 0.003]. In conclusion, carpal tunnel release is associated with significant cutaneous reinnervation, which correlates with the degree of functional improvement and is associated with a transcriptional programme relating to morphogenesis and inflammatory processes. The most highly dysregulated gene ADCYAP1 (encoding PACAP) was associated with reinnervation and, given that this peptide signals through G-protein coupled receptors, this signalling pathway provides an interesting therapeutic target for human sensory nerve regeneration.

Small and large fiber sensory polyneuropathy in type 2 diabetes: Influence of diagnostic criteria on neuropathy subtypes

Diabetic polyneuropathy (DPN) can be classified based on fiber diameter into three subtypes: small fiber neuropathy (SFN), large fiber neuropathy (LFN), and mixed fiber neuropathy (MFN). We examined the effect of different diagnostic models on the frequency of polyneuropathy subtypes in type 2 diabetes patients with DPN. This study was based on patients from the Danish Center for Strategic Research in Type 2 Diabetes cohort. We defined DPN as probable or definite DPN according to the Toronto Consensus Criteria. DPN was then subtyped according to four distinct diagnostic models. A total of 277 diabetes patients (214 with DPN and 63 with no DPN) were included in the study. We found a considerable variation in polyneuropathy subtypes by applying different diagnostic models independent of the degree of certainty of DPN diagnosis. For probable and definite DPN, the frequency of subtypes across diagnostic models varied from: 1.4% to 13.1% for SFN, 9.3% to 21.5% for LFN, 51.4% to 83.2% for MFN, and 0.5% to 14.5% for non-classifiable neuropathy (NCN). For the definite DPN group, the frequency of subtypes varied from: 1.6% to 13.5% for SFN, 5.6% to 20.6% for LFN, 61.9% to 89.7% for MFN, and 0.0% to 6.3% for NCN. The frequency of polyneuropathy subtypes depends on the type and number of criteria applied in a diagnostic model. Future consensus criteria should clearly define sensory functions to be tested, methods of testing, and how findings should be interpreted for both clinical practice and research purpose.

Diagnosis and prevalence of diabetic polyneuropathy: a cross-sectional study of Danish patients with type 2 diabetes

BACKGROUND AND PURPOSE

Diabetic polyneuropathy (DPN) is a common complication of diabetes. Using the Toronto criteria for diabetic polyneuropathy and the grading system for neuropathic pain, the performance of neuropathy scales and questionnaires were assessed by comparing them to a clinical gold standard diagnosis of DPN and painful DPN in a cohort of patients with recently diagnosed type 2 diabetes.

METHODS

A questionnaire on neuropathy and pain was sent to a cohort of 5514 Danish type 2 diabetes patients. A sample of 389 patients underwent a detailed clinical examination and completed neuropathy questionnaires and scales.

RESULTS

Of the 389 patients with a median diabetes duration of 5.9 years, 126 had definite DPN (including 53 with painful DPN), 88 had probable DPN and 53 had possible DPN. There were 49 patients with other causes of polyneuropathy, neuropathy symptoms or pain, 10 with subclinical DPN and 63 without DPN. The sensitivity of the Michigan Neuropathy Screening Instrument questionnaire to detect DPN was 25.7% and the specificity 84.6%. The sensitivity of the Toronto Clinical Neuropathy Scoring System, including questionnaire and clinical examination, was 62.9% and the specificity was 74.6%.

CONCLUSIONS

Diabetic polyneuropathy affects approximately one in five Danish patients with recently diagnosed type 2 diabetes but neuropathic pain is not as common as previously reported. Neuropathy scales with clinical examination perform better compared with questionnaires alone, but better scales are needed for future epidemiological studies.

Somatosensory predictors of response to pregabalin in painful chemotherapy-induced peripheral neuropathy: a randomized, placebo-controlled, crossover study

Painful chemotherapy-induced peripheral neuropathy (CIPN) is a debilitating and treatment-resistant sequela of many chemotherapeutic medications. Ligands of α2δ subunits of voltage-gated Ca channels, such as pregabalin, have shown efficacy in reducing mechanical sensitivity in animal models of neuropathic pain. In addition, some data suggest that pregabalin may be more efficacious in relieving neuropathic pain in subjects with increased sensitivity to pinprick. We hypothesized that greater mechanical sensitivity, as quantified by decreased mechanical pain threshold at the feet, would be predictive of a greater reduction in average daily pain in response to pregabalin vs placebo. In a prospective, randomized, double-blinded study, 26 patients with painful CIPN from oxaliplatin, docetaxel, or paclitaxel received 28-day treatment with pregabalin (titrated to maximum dose 600 mg per day) and placebo in crossover design. Twenty-three participants were eligible for efficacy analysis. Mechanical pain threshold was not significantly correlated with reduction in average pain (P = 0.97) or worst pain (P = 0.60) in response to pregabalin. There was no significant difference between pregabalin and placebo in reducing average daily pain (22.5% vs 10.7%, P = 0.23) or worst pain (29.2% vs 16.0%, P = 0.13) from baseline. Post hoc analysis of patients with CIPN caused by oxaliplatin (n = 18) demonstrated a larger reduction in worst pain with pregabalin than with placebo (35.4% vs 14.6%, P = 0.04). In summary, baseline mechanical pain threshold tested on dorsal feet did not meaningfully predict the analgesic response to pregabalin in painful CIPN.

Abstract P5-12-01: A novel gene expression signature prognostic for both locoregional and distant failure and predictive for adjuvant radiotherapy

Background: Most patients with early stage breast cancer (BC) are treated with adjuvant radiotherapy (RT) following breast conserving surgery (BCS) to prevent locoregional recurrences (LRR). No predictive tools are currently available to select patients for RT, resulting in considerable over- and under treatment. We aimed to create and validate a gene expression-based classifier to prognosticate for LRR and to stratify patients for treatment with RT.

Patients and methods: A 27-gene expression signature was developed using three publicly available early stage BC gene expression datasets where patients were treated with RT and had detailed local recurrence information. The largest of the datasets was used to train the signature, and the other two datasets were used for signature refinement. As age was the strongest clinical factor for the endpoint in the training dataset, it was included in the model, resulting in a final clinical-genomic classifier of 27 genes and age. The classifier was locked before external validation in the SweBCG91-RT trial. This phase III clinical trial included primary tumors from 765 patients and for which gene expression data was available. The trial randomized node-negative BC patients to +/- RT following BCS, with sparse use of adjuvant systemic treatment (9%) and a median follow-up of 14.0 years for LRR in patients free from event. The classifier was validated using Cox regression with LRR as the primary endpoint, and hazard ratios (HRs) were calculated using the raw continuous classifier score (range: 0.5 to 2.5).

Results: The novel classifier was highly prognostic for LRR in SweBCG91-RT patients treated with RT (HR=7.5[3.3-16.9], p&lt;0.001), and remained prognostic in multivariate analysis (MVA) that included systemic treatment, subtype and grade (HR=7.2[3.1-16.4], p&lt;0.001). To a lesser extent, the classifier was also prognostic for LRR in patients not treated with RT (HR=1.9[1.0-3.5], p=0.03; MVA HR=1.9[1.0-3.3], p=0.05). Patients at high risk of LRR had a smaller effect of RT, and the treatment predictive potential was confirmed by testing for interaction (pinteraction=0.008). In patients treated with RT, age and the genomic component of the model were both prognostic for LRR (p&lt;0.01) as well as predictive for RT response (pinteraction&lt;0.05) and provided independent information (p&lt;0.01). The combined classifier has increased performance over its individual components (10-year AUC=0.72, 0.67, 0.65 for the classifier, age, and genomic component, respectively). While the novel signature was prognostic for metastasis (HR=4.3[2.3-7.8], p&lt;0.0001), calculated scores from previously published signatures to the metastasis endpoint, including the Oncotype-like score, were not prognostic for LRR.

Conclusions: This novel gene expression signature is highly prognostic for LRR, can identify patients at risk of LRR despite RT, and appears to be treatment predictive for adjuvant RT. Furthermore, the current signature is highly prognostic for metastasis. In contrast, calculated scores of previously published signatures modeled for the metastasis endpoint had inferior performance for LRR. These results underscore both the importance of signatures prognostic for LRR and the similarities in the biology of LRR and distant failure.

Citation Format: Sjöström M, Chang SL, Fishbane N, Davicioni E, Zhao SG, Hartman L, Holmberg E, Feng FY, Speers CW, Pierce LJ, Malmström P, Fernö M, Karlsson P. A novel gene expression signature prognostic for both locoregional and distant failure and predictive for adjuvant radiotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P5-12-01.

Abstract PD8-11: Distribution of locoregional breast cancer recurrences in relation to previous radiotherapy and biological subtype

Background: Adjuvant locoregional radiotherapy (LRRT) reduces risk of locoregional failures (LRF) and improves survival for node positive breast cancer (BC) patients. However, LRRT increases the risk for toxicity as edema in the arm, lung cancer and cardiac mortality. Modern radiotherapy allows a more conform therapy which makes knowledge of LRF-patterns very important, in order not to underdose volumes with high risk for microscopic disease and simultaneously restrict dose to risk organs. In addition, BC-subtype may affect radiosensitivity and could possibly be used to individualize LRRT in the future.

Methods: We investigated outcome for BC-patients receiving LRRT in the Southwest Sweden (2004-2008) in order to identify LRFs. During this period patients with &gt;3 positive lymph nodes were given LRRT (50Gy in 2Gy fractions) to the breast/thoracic wall, axilla level II+III, supra- and infraclavicular lymph nodes according to a target definition atlas introduced in 2002. Patients with LRF as first event were identified, with distant failures and death considered as competing risks. The anatomical distribution of LRF was compared with the contouring atlas, radiotherapy given, and biological subtype based on immunohistochemistry.

Results: 904 patients received LRRT. Median follow-up time was 9.8 years (0.2-14.6) for patients without an event. 59 patients (6,5%) developed a LRF, 30 of which were local failures (LF) and 31 regional failures (RF) (2 simultaneous LF/RF). Median time to LRF was 2.8 years. 37 of the 59 (63%) LRF-patients developed generalized disease within 3 months from the LRF. Of the 845 patients without LRF 316 developed distant metastases as first recurrence, 1 an isolated RF in the contralateral axilla, 64 died from other causes, and for 5 patients recurrence-status was unclear. 459 were alive at end of follow-up.

Of the LF 19 developed after mastectomy (MRM) and 11 after breast conserving surgery (BCS). LF-location after MRM: 9 in-field, 6 at field margin, 2 both in/out of field, 1 out of field, and for 1 not yet determined. After BCS: 8 in-field, 1 at field margin, and for 2 not yet determined. Of the RF 28 developed after MRM and 3 after BCS. Location of RF after MRM: 11 in-field, 6 at field margin, 1 both in/out of field, 2 out of field, and for 8 not yet determined. After BCS: 1 in-field, 1 at field margin, and 1 not yet determined. The most common location for RF close to /out of field was superior to the treated area in fossa supraclavicularis.

Biological approximate subtype was available for 885 of the primary tumours; luminal (ER+ and/or PR+ HER2-/?) 67% (589/885), HER2+ 19% (169/885), triple negative (ER- and PR- HER2-/?) (TN) 14% (127/885). Subtype distribution of BC later causing LRF despite LRRT was: luminal 44% (26/59), HER2+ 27% (16/59), TN 29% (17/59). Among primary tumours causing a LRF within irradiated volume 77% (24/31) were HER2+ or TN.

Conclusion: In this high risk cohort of BC-patients, we found a low incidence of LRFs. The majority of LRFs developed within irradiated volume. BCs of the HER2+ and TN-subtype may be more radioresistant and have a higher risk of LRF. Updated information as well as figures mapping all recurrences in relation to previous LRRT will be presented at the symposium.

Citation Format: Adra J, Karlsson P, Killander F, Lundstedt D, Alkner S. Distribution of locoregional breast cancer recurrences in relation to previous radiotherapy and biological subtype [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr PD8-11.

Abstract P2-06-19: The effect of UBE2C expression on intrinsic chemosensitivity in breast cancer cell lines

Background: The ubiquitin-proteasome pathway plays a crucial role in cancer-related processes by inducing cell cycle arrest through the degradation of mitotic cyclins and other cell cycle regulatory proteins. We recently showed that elevated levels of ubiquitin-conjugating enzyme E2C (UBE2C) were associated with aggressive tumor features and unfavorable clinical outcome in breast carcinoma (BC). UBE2C suppression has been achieved using the FDA-approved proteasome inhibitor bortezomib (VELCADE®) in colorectal carcinoma, but little is known about the efficacy of UBE2C-targeted therapy with proteasome inhibitors in breast cancer.

Methods: Cell viability assays were used to determine the intrinsic chemosensitivity of five BC cell lines (MCF-7, MDA-MB-436, HCC38, HCC1395, and ZR-75-30; stratified by UBE2C expression and ER status) and the MCF-10A epithelial cell line to proteasome inhibitors (n=8), mitosis inhibitors (n=2), and platinum agents (n=3). UBE2C expression analysis was performed using quantitative real-time PCR and Western blot. IC50 values and growth inhibition metrics (GR50 and GRmax) were calculated for each compound to determine drug potency and efficiency after 24 hour treatment. Proteasome activity was assessed using bortezomib-treated cells.

Results: Heterogeneous UBE2C expression levels were found in the different cell lines, with higher UBE2C levels in ER-negative BC cell lines (HCC38, HCC1395, MDA-MB-436) than ER-positive BC (MCF-7 and ZR-75-30) and MCF-10A control cells (ER-negative). Proteasome inhibition levels close to 50% and 100% were seen in all cell lines after 10 nM and 100 - 1000 nM bortezomib, respectively. As expected, bortezomib blocked cell cycle progression by inducing G2/M phase arrest in HCC38 cells. Due to differences in cell growth rates, calculation of the IC50 value was an ineffective method to determine drug potency. In contrast, the normalized growth rate inhibition method with GR50 and GRmax values demonstrated a correlation between sensitivity to proteasome inhibitors in ER-negative BC cell lines and high UBE2C expression levels. However, MDA-MB-436 cells (GR50, range 1.8-286.1 nM; GRmax, range -0.42- -0.93) were generally less sensitive to proteasome inhibitors than HCC38 cells (GR50, range 8.2-936.8 nM; GRmax, range -0.97- -0.99) though both cell lines were ER-negative, which was possibly due to the lower expression of UBE2C in MDA-MB-436 cells. Compared with the other tested drugs, no cell line was sensitive to the mitosis inhibitors and platinum agents were most effective in HCC38 cells.

Conclusions: Taken together, these findings suggest an association between UBE2C expression and response to proteasome inhibition, regardless of ER status.

Citation Format: Parris TZ, Larsson P, Biermann J, Engqvist H, Werner-Rönnerman E, Kovács A, Karlsson P, Helou K. The effect of UBE2C expression on intrinsic chemosensitivity in breast cancer cell lines [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-06-19.

Abstract P3-07-09: Tumour clonality in paired invasive breast carcinomas

Background: Multiple invasive breast tumours may represent either independent primary tumours or clonal recurrences of the first tumour, where the same progenitor cell gives rise to all of the detected tumours. Consequently, the driver events for the progenitor cell need to have been identical in early tumour development. Molecular classification of tumour clonality is not currently evaluated in multiple invasive breast carcinomas, despite evidence suggesting common clonal origins. Furthermore, there is no consensus about which type of biological data (e.g. copy number, mutation, histology) and especially which statistical method is most suitable to distinguish clonal recurrences from independent primary tumours.

Methods: Thirty-seven invasive breast tumour pairs were stratified by laterality (bilateral vs. ipsilateral) and the time interval between the diagnoses of the first and second tumours (synchronous vs. metachronous). Both tumours from the same patient were analysed by integrating clinical characteristics (n = 37), DNA copy number (n = 37), DNA methylation (n = 8), gene expression microarray (n = 7), RNA sequencing (n = 3), and SNP genotyping data (n = 3). Different statistical methods, e.g. the diagnostic similarity index (SI), distance measure, shared segment analysis etc., were used to classify the tumours from the same patient as clonally related recurrences or independent primary tumours.

Results: The SI applied on DNA copy numbers derived from aCGH (array comparative genomic hybridization) data was determined as the strongest indicator of clonal relatedness as it showed the highest concordance with all other methods. The distance measure was the most conservative method and the shared segment analysis most liberal. Concordant evidence for tumour clonality was found in 46% (17/37) of the patients. Notably, no significant association was found between the clinical characteristics and molecular tumour features.

Conclusions: A more accurate classification of clonal relatedness between multiple breast tumours may help to mitigate treatment failure and relapse by integrating tumour-associated molecular features, clinical parameters, and statistical methods. In cases of extremely similar or different tumour pairs, the results showed consistency regardless of the method used. The SI can be easily integrated into clinical routine using FFPE samples to obtain copy number data. However, clinical guidelines with exact thresholds need to be defined to standardize clonality testing in a routine diagnostic setting.

Citation Format: Biermann J, Parris TZ, Nemes S, Danielsson A, Engqvist H, Werner Rönnerman E, Forssell-Aronsson E, Kovács A, Karlsson P, Helou K. Tumour clonality in paired invasive breast carcinomas [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-07-09.

Corneal confocal microscopy as a tool for detecting diabetic polyneuropathy in a cohort with screen-detected type 2 diabetes: ADDITION-Denmark

AIMS

In this cross-sectional study, we explored the utility of corneal confocal microscopy (CCM) measures for detecting diabetic polyneuropathy (DPN) and their association with clinical variables, in a cohort with type 2 diabetes.

METHODS

CCM, nerve conduction studies, and assessment of symptoms and clinical deficits of DPN were undertaken in 144 participants with type 2 diabetes and 25 controls. DPN was defined according to the Toronto criteria for confirmed DPN.

RESULTS

Corneal nerve fiber density (CNFD) was lower both in participants with confirmed DPN (n = 27) and in participants without confirmed DPN (n = 117) compared with controls (P = 0.04 and P = 0.01, respectively). No differences were observed for CNFD (P = 0.98) between participants with and without DPN. There were no differences in CNFL and CNBD between groups (P = 0.06 and P = 0.29, respectively). CNFD was associated with age, height, total- and LDL cholesterol.

CONCLUSIONS

CCM could not distinguish patients with and without neuropathy, but CNFD was lower in patients with type 2 diabetes compared to controls. Age may influence the level of CCM measures.

Ethyl carbamate in Swedish and American smokeless tobacco products and some factors affecting its concentration

BACKGROUND

We are interested in comparing the levels of harmful or potentially harmful constituents in Swedish and American smokeless tobacco products (STPs). We report here the concentrations of the IARC Group 2 A (probable human) carcinogen ethyl carbamate (EC) in seventy commercial STPs from the US and Sweden, representing 80-90% of the market share of the major STP categories in these countries. We also examine the effects of various additives, processing and storage conditions on EC concentrations in experimental snus samples.

RESULTS

EC was determined from aqueous extracts of the STPs using ultra performance liquid chromatography tandem mass spectrometry (UPLC/MS/MS). EC was undetectable (< 20 ng/g wet weight basis WWB) in 60% of the commercial STPs, including all the chewing tobacco (CT), dry snuff (DS), hard pellet (HP), soft pellet (SP), and plug products. Measurable levels of EC were found in 11/16 (69%) of the moist snuff (MS) samples (average 154 ng/g in those samples containing EC) and 19/32 (59%) of the Swedish snus samples (average 35 ng/g). For the experimental snus samples, EC was only observed in ethanol treated samples. EC concentrations increased significantly with ethanol concentrations (0-4%) and with storage time (up to 24 weeks) and temperature (8 °C vs 20 °C). EC concentrations were lower at lower pHs but were unaffected by adding nitrogenous precursors identified from food studies (citrulline and urea), increasing water content or by pasteurisation. Added EC was stable in the STP matrix, but evaporative losses were significant when samples were stored for several weeks in open containers at 8 °C.

CONCLUSIONS

EC was found in measurable amounts only in some moist STPs i.e. pasteurised Swedish snus and unpasteurised US MS; it is not a ubiquitous contaminant of STPs. The presence of ethanol contributed significantly to the presence of EC in experimental snus samples, more significantly at higher pH levels. Sample age also was a key determinant of EC content. In contrast, pasteurisation and fermentation do not appear to directly influence EC levels. Using published consumption rates and mouth level exposures, on average STP consumers are exposed to lower EC levels from STP use than from food consumption.

A pain in the skin. Regenerating nerve sprouts are distinctly associated with ongoing burning pain in patients with diabetes

BACKGROUNDS

Patients with diabetic polyneuropathy commonly suffer from ongoing burning pain and dynamic mechanical allodynia. In this clinical and skin biopsy study, we aimed at assessing how intraepidermal regenerating nerve sprouts are associated with these two types of pain.

METHODS

We consecutively enrolled 85 patients with diabetic polyneuropathy. All patients underwent skin biopsy at the distal leg. Intraepidermal nerve fibres were immunostained with the anti-protein gene product 9.5 (PGP9.5) to quantify all intraepidermal nerve fibres, and the growth-associated protein 43 (GAP43) to quantify regenerating nerve sprouts.

RESULTS

We found that the GAP43-stained intraepidermal nerve fibre density and the ratio GAP43/PGP9.5 were significantly higher in patients with ongoing burning pain than in those without. The area of receiver operating characteristic (ROC) curve for the ratio GAP43/PGP9.5 was 0.74 and yielded a sensitivity and specificity for identifying ongoing burning pain of 72% and 71%, respectively. Conversely, although the density of PGP9.5 and GAP43 intraepidermal nerve fibre was higher in patients with dynamic mechanical allodynia than in those without, this difference was statistically weak and the ROC curve analysis of skin biopsy variables for this type of pain failed to reach the statistical significance.

CONCLUSION

Our clinical and skin biopsy study showed that ongoing burning pain was strongly associated with regenerating sprouts, as assessed with GAP43 immunostaining. This finding improves our understanding on the mechanisms underlying neuropathic pain in patients with diabetic polyneuropathy and suggests that the GAP43/PGP 9.5 ratio might be used as an objective marker for ongoing burning pain due to regenerating sprouts.

SIGNIFICANCE

Our skin biopsy study showing that regenerating sprouts, as assessed with GAP43-staining, were strongly associated with ongoing burning pain, improves our knowledge on the mechanisms underlying neuropathic pain in patients with diabetes.

Abstract P5-18-01: Extended continuous vs intermittent adjuvant letrozole in postmenopausal women with lymph node-positive, early breast cancer (IBCSG 37-05/BIG 1-07 SOLE): Impact on patient-reported symptoms and quality of life

Background: SOLE efficacy results presented at ASCO 2017 showed that extended intermittent vs continuous letrozole for 5 years did not improve disease-free survival in postmenopausal women who had received 4-6 years of adjuvant endocrine therapy for hormone-receptor positive (HR+), lymph-node positive breast cancer. Previous studies showed that the burden by symptoms related to endocrine therapy can be substantial. Even if symptoms improve during the treatment course, extending treatment implies continuation of symptoms. We compared differences in patient-reported symptoms (PRS) and quality of life (QoL) between extended continuous and intermittent letrozole over the first two years of trial treatment.

Methods: From Nov 2007 to Dec 2010, 956 postmenopausal women who were disease-free following 4-6 years of prior adjuvant endocrine therapy for HR+, node-positive breast cancer were enrolled in the QoL substudy of the randomized phase III trial SOLE at selected centers. Patients receive extended continuous letrozole (2.5 mg daily) for 5 years or intermittent letrozole, taken for the first 9 months of years 1-4, and 12 months in year 5. 955 patients completed the 18-item Breast Cancer Prevention Trial (BCPT) Symptom Scales and further symptom-specific and global QoL indicators at baseline, and at 6, 12, 18 and 24 months after randomization. Differences in change of PRS and QoL from baseline between the two administration schedules were tested at 12 and 24 months for 8 symptom scales, 4 additional symptom and 4 global QoL indicators using mixed models with repeated measures.

Results: Small changes in PRS and QoL scores were observed between baseline and 12 months after randomization, i.e. at the end of the first treatment-free interval in the intermittent arm. These changes showed a consistent pattern of greater worsening for patients receiving continuous compared to patients receiving intermittent letrozole. Patients receiving continuous letrozole reported a significantly greater worsening in vaginal problems (p&lt;.02), musculoskeletal pain (p&lt;.03), sleep disturbance (p&lt;.01), physical wellbeing (p&lt;.01) and mood (p&lt;.03). At 24 months (after 2nd treatment-free interval) patients with intermittent letrozole reported a greater improvement in hot flushes (p&lt;.03) than those with continuous letrozole. Changes in the other outcomes did not significantly differ between arms at 24 months.

Conclusion: Although changes in PRS and QoL were small, there was a consistent pattern favoring the intermittent arm. For several symptoms and global QoL indicators, significantly less worsening was observed with the intermittent administration, mainly during the first year of extended treatment, due to small improvements during the treatment-free interval. Froma QoL perspective, women who suffer from endocrine side-effects in the extended setting may benefit from an intermittent administration.

Citation Format: Ribi K, Luo W, Colleoni M, Karlsson P, Chirgwin J, Aebi S, Jerusalem G, Neven P, Di Lauro V, Gomez HL, Ruhstaller T, Abdi E, Di Leo A, Müller B, Maibach R, Gelber RD, Goldhirsch A, Coates AS, Regan MM, Bernhard J. Extended continuous vs intermittent adjuvant letrozole in postmenopausal women with lymph node-positive, early breast cancer (IBCSG 37-05/BIG 1-07 SOLE): Impact on patient-reported symptoms and quality of life [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-18-01.

Abstract GS5-08: A validation of DCIS biological risk profile in a randomised study for radiation therapy with 20 year follow-up (SweDCIS)

Background: Women diagnosed with ductal carcinoma in situ (DCIS) and their physicians need tools that assess individualized risk and predict treatment benefit. A DCIS biologic signature was previously validated in an observational study at Kaiser Permanente NW. We evaluated the results of the signature for predictive utility in a national randomized clinical trial (SweDCIS) by assessing the 10-year benefit of adjuvant radiotherapy (RT) on ipsilateral breast event (IBE) and invasive breast cancer (IBC) risks.

Methods: The signature was validated in a prospective-retrospective study in women from the SweDCIS trial (n=1046) performed by the Swedish Breast Cancer Group. Women were treated with breast conserving surgery (BCS) between 1987-1999 and randomized to RT or no RT. A central pathology review of paraffin embedded tissue blocks (n=873) was performed at Uppsala University (UU). Freshly cut slides were provided to PreludeDx for biomarker testing. Extended follow-up of SweDCIS was published in 2014.

A panel of biomarkers (HER2, PR, Ki67, COX2, p16/INK4A, FOXA1 and SIAH2) were assayed and scored in PreludeDx's CLIA lab by board-certified pathologists. Continuous Decision Scores (DS) were calculated with the biologic signature using the biomarker and clinical factors (age, size, margin, and palpability) blinded to patient outcome. The DS results were provided to the Uppsala Regional Cancer Center for analysis. A predefined and co-developed statistical analysis plan was executed. Absolute 10-year RT benefit was assessed using Kaplan-Meier survival analysis. Hazard ratios (HR) were determined using Cox proportional hazards analysis and the interaction of the DS and RT benefit was assessed.

Results: Complete biomarker and clinical information was available in 584 women. In women with clear margins (n=506), 78 IBEs, including 31 IBCs, were recorded within 10 years of diagnosis. The multivariate analysis of DS (0-10 unit scale) and the RT interaction was significant for risk of IBC (p=0.048) and IBE (p&lt;0.001) at 10 years. The DS defined an elevated risk group (&gt;3) for which there was pronounced 10-year benefit of RT (p=0.01) with an absolute risk reduction of 9% for IBC (Table 1). The corresponding low risk group (≤3), which included 48% of all patients, demonstrated no significant RT benefit (p=0.70) with an absolute risk reduction of 1%. The continuous DS variable was correlated with IBE risk, HR 1.49/per 5 units 95%CI[1.02,2.18] (p=0.038), in addition to the RT benefit for IBE in low (p=0.04) and elevated (p&lt;0.001) risk groups.

Table 1. 10-year RT benefit in women from the SweDCIS trial.DS Risk GroupsIBC eventsIn Situ or IBC eventsnAbsolute RT-benefitHR [95%CI] Absolute RT-benefit HR [95%CI]Low Risk Group (DS≤3)2431%0.83 [0.32, 2.16]9%0.48 [0.24-0.97]Elevated Risk Group (DS&gt;3)2639%0.24 [0.08, 0.73]17%0.31 [0.17-0.59]

Discussion: Evaluation of the SweDCIS trial validated prognostic and RT predictive utility of the biologic signature. Women diagnosed with DCIS and treated with BCS±RT were stratified into clinically relevant low and elevated risk groups (≤3 vs &gt;3). Women in the elevated risk group had twice the treatment benefit for IBC from RT compared to prior randomized trials, while the low risk group had no benefit from RT.

Citation Format: Wärnberg F, Garmo H, Folkvaljon Y, Holmberg L, Karlsson P, Sandelin K, Linke S, Lyle S, Simin K, Leesman G, Barry T, Savala J, Whitworth P, Bremer T. A validation of DCIS biological risk profile in a randomised study for radiation therapy with 20 year follow-up (SweDCIS) [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr GS5-08.

Abstract P3-04-07: Novel genetic features associated with 8p11-p12 amplification in breast carcinoma

Background: Genome instability contributes to the neoplastic phenotype by promoting gene loss and duplications, which in turn can have a detrimental effect on patient outcome by inactivating tumor suppressor genes or hyperactivating oncogenes. In breast carcinoma, DNA amplification of the 8p11-p12 genomic region has been associated with tumor progression and poor prognosis. The aim of this study was to characterize recurrent genetic features (other than DNA amplification) associated with 8p11-p12 amplification in breast carcinoma.

Methods: DNA copy number profiling data for 229 primary invasive breast carcinomas (corresponding to 185 patients diagnosed in Western Sweden between 1988 and 1999) were evaluated to identify 8p11-p12 amplified cases. Illumina paired-end whole transcriptome sequencing (RNA-seq) and whole-genome SNP genotyping were subsequently performed on 23 breast carcinomas harboring high-level regional 8p11-p12 amplification to characterize recurrent genetic variants (SNPs and indels), expressed gene fusions, gene expression profiles and allelic imbalances. The 23 samples were stratified into the molecular subtypes, resulting in 16 Luminal B/HER2-, two Luminal B/HER2+, four HER2/ER-, and one Basal-like sample. The Cancer Genome Atlas (TCGA) RNA-seq data for 10 primary breast carcinomas lacking the 8p11-p12 amplicon (SNP segmented mean &lt; 0.4) were used as controls. Gene fusions were validated using dual-color fluorescence in situ hybridization (FISH) with co-hybridized biotin-16-dUTP and dioxigenin-11-dUTP labeled bacterial artificial chromosome (BAC) probes.

Results: Here, we report that despite the high number of gene fusions (133±31 (±SEM)) and exonic variants (411±16) identified per tumor, few gene fusions (n=46) and exonic variants (n=11) spanned the 8p11-p12 genomic region. Gene fusions predominantly contained at least one fusion partner spanning non-coding RNAs (ncRNAs; 86%), in particular MALAT1, which is induced by estrogen and of prognostic value in breast cancer. The majority of fusion breakpoints were associated with DNA copy number gains and losses, as well as, extensive intratumoral heterogeneity for specific fusion events. Intriguingly, novel 8p11-p12 amplification-specific genetic variants (HIST1H1E frameshift insertion, UQCRHL nonsynonymous SNV, MTUS1 frameshift insertion, NPIPA5 frameshift deletion) were identified that also resulted in mutation-dependent changes in gene expression levels.

Conclusions: Taken together, these findings have provided further insight into the genetic landscape of 8p11-p12 amplified breast carcinomas, including novel gene fusions and genetic variants. However, further studies are required to develop effective strategies to target 8p11-p12 amplification in breast carcinoma.

Citation Format: Parris TZ, Biermann J, Engqvist H, Werner Rönnerman E, Truvé K, Nemes S, Forssell-Aronsson E, Solinas G, Kovács A, Karlsson P, Helou K. Novel genetic features associated with 8p11-p12 amplification in breast carcinoma [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-04-07.

De-escalating and escalating treatments for early-stage breast cancer: the St. Gallen International Expert Consensus Conference on the Primary Therapy of Early Breast Cancer 2017

The 15th St. Gallen International Breast Cancer Conference 2017 in Vienna, Austria reviewed substantial new evidence on loco-regional and systemic therapies for early breast cancer. Treatments were assessed in light of their intensity, duration and side-effects, seeking where appropriate to escalate or de-escalate therapies based on likely benefits as predicted by tumor stage and tumor biology. The Panel favored several interventions that may reduce surgical morbidity, including acceptance of 2 mm margins for DCIS, the resection of residual cancer (but not baseline extent of cancer) in women undergoing neoadjuvant therapy, acceptance of sentinel node biopsy following neoadjuvant treatment of many patients, and the preference for neoadjuvant therapy in HER2 positive and triple-negative, stage II and III breast cancer. The Panel favored escalating radiation therapy with regional nodal irradiation in high-risk patients, while encouraging omission of boost in low-risk patients. The Panel endorsed gene expression signatures that permit avoidance of chemotherapy in many patients with ER positive breast cancer. For women with higher risk tumors, the Panel escalated recommendations for adjuvant endocrine treatment to include ovarian suppression in premenopausal women, and extended therapy for postmenopausal women. However, low-risk patients can avoid these treatments. Finally, the Panel recommended bisphosphonate use in postmenopausal women to prevent breast cancer recurrence. The Panel recognized that recommendations are not intended for all patients, but rather to address the clinical needs of the majority of common presentations. Individualization of adjuvant therapy means adjusting to the tumor characteristics, patient comorbidities and preferences, and managing constraints of treatment cost and access that may affect care in both the developed and developing world.

Stakeholders' views of the introduction of assistive technology in the classroom: How family-centred is Australian practice for students with cerebral palsy?

BACKGROUND

With family-centred care widely recognized as a cornerstone for effective assistive technology service provision, the current study was undertaken to investigate to what extent such approaches were used by schools when assistive technology assessments and implementation occurred in the classroom.

METHOD

In this cross-sectional study, we compare survey results from parents (n = 76), school staff (n = 33) and allied health professionals (n = 65) with experience in the use of high-tech assistive technology. Demographic characteristics and the stakeholders' perceived helpfulness and frequency attending assessment and set-up sessions were captured. To evaluate how family-centred the assistive technology services were perceived to be, the parents filled out the Measure of Processes of Care for Caregivers, and the professionals completed the Measure of Processes of Care for Service Providers. Descriptive statistics and one-way analysis of variance were used to conduct the data analysis.

RESULTS

Findings show that parents are more involved during the assessment stage than during the implementation and that classroom teachers are often not involved in the initial stage. Speech pathologists in particular are seen to be to a great extent helpful when implementing assistive technology in the classroom. This study found that family-centred service is not yet fully achieved in schools despite being endorsed in early intervention and disability services for over 20 years. No statistically significant differences were found with respect to school staff and allied health professionals' roles, their years of experience working with students with cerebral palsy and the scales in the Measure of Processes of Care for Service Providers.

CONCLUSION

To enhance the way technology is matched to the student and successfully implemented, classroom teachers need to be fully involved in the whole assistive technology process. The findings also point to the significance of parents' involvement, with the support of allied health professionals, in the process of selecting and implementing assistive technology in the classroom.

Improved sampling and analysis of images in corneal confocal microscopy

INTRODUCTION

Corneal confocal microscopy (CCM) is a noninvasive clinical method to analyse and quantify corneal nerve fibres in vivo. Although the CCM technique is in constant progress, there are methodological limitations in terms of sampling of images and objectivity of the nerve quantification. The aim of this study was to present a randomized sampling method of the CCM images and to develop an adjusted area-dependent image analysis. Furthermore, a manual nerve fibre analysis method was compared to a fully automated method.

METHODS

23 idiopathic small-fibre neuropathy patients were investigated using CCM. Corneal nerve fibre length density (CNFL) and corneal nerve fibre branch density (CNBD) were determined in both a manual and automatic manner. Differences in CNFL and CNBD between (1) the randomized and the most common sampling method, (2) the adjusted and the unadjusted area and (3) the manual and automated quantification method were investigated.

RESULTS

The CNFL values were significantly lower when using the randomized sampling method compared to the most common method (p = 0.01). There was not a statistical significant difference in the CNBD values between the randomized and the most common sampling method (p = 0.85). CNFL and CNBD values were increased when using the adjusted area compared to the standard area. Additionally, the study found a significant increase in the CNFL and CNBD values when using the manual method compared to the automatic method (p ≤ 0.001).

CONCLUSION

The study demonstrated a significant difference in the CNFL values between the randomized and common sampling method indicating the importance of clear guidelines for the image sampling. The increase in CNFL and CNBD values when using the adjusted cornea area is not surprising. The observed increases in both CNFL and CNBD values when using the manual method of nerve quantification compared to the automatic method are consistent with earlier findings. This study underlines the importance of improving the analysis of the CCM images in order to obtain more objective corneal nerve fibre measurements.

Abstract P1-09-03: Relative radioresistency in triple negative tumors in the SweBCG91-RT randomized clinical trial

Introduction: Breast-conserving surgery (BCS) with adjuvant whole breast radiation therapy (WBRT) is the standard treatment for a majority of early breast cancer patients. No predictive biomarkers for RT are in use and most patients are cured by surgery alone, and are thus over-treated. Further, some patients suffer a relapse despite WBRT, and may have benefited from mastectomy or more aggressive postoperative treatment. Gene expression tests can be used to predict risk of distant recurrence and effect of adjuvant systemic therapy, and can reveal the intrinsic subtype of the tumor. A surrogate method of determining intrinsic subtype based on high quality centralized immunohistochemistry (IHC) has been proposed with criteria set up by the St Gallen consensus group 2013. The intrinsic subtypes provide prognostic information and are treatment predictive for chemotherapy, but the predictive potential for WBRT has not been conclusively determined.

Aim: To evaluate the effect of WBRT on ipsilateral breast tumor recurrence (IBTR), in patients with tumors of different intrinsic subtypes.

Methods: Tumor tissue from FFPE blocks were collected from 1003 breast cancer patients with node negative, stage I-II disease, randomized to BCS with or without WBRT, in the randomized SweBCG RT-91 trial between 1991-1997. Systemic adjuvant treatment was administered according to regional guidelines, but was sparsely used. Median follow-up was 15.2 years. Tissue microarrays were constructed and stained for estrogen receptor (ER), progesterone receptor (PgR), human epidermal growth factor receptor 2 (Her2) and Ki-67. SISH was used to determine amplification of samples scored 2+ for Her2. Centralized evaluation was performed by two pathologists subspecialized in breast pathology. Endpoint IBTR within 10 years was considered with a cumulative incidence and competing risks approach. P-values were calculated with the cause-specific logrank test and hazard ratios (HR) with cause specific Cox regression. Multivariate models, with or without an interaction term between subtype and WBRT, were compared to formally test if the effect of RT differs between subtypes.

Results: We were able to stain and score 958 out of 1003 tumors. These were classified as Luminal A-like (n=554), Luminal B-like (Her2-negative, n=259), triple negative (n=81) and Her2-positive (any ER status, n=64). WBRT reduced the frequency of IBTR for Luminal A-like tumors (19% vs 9%, HR 0.46 (0.28-0.74), p=0.001), Luminal B-like tumors (24% vs 8%, HR 0.30 (0.14-0.61), p&lt;0.001) and triple negative tumors (21% vs 6%, HR 0.25 (0.05-1.12), p=0.05), but not for Her2-positive tumors (15% vs 19%, HR 1.29 (0.38-4.4), p=0.69). However, the overall difference in WBRT effect between subtypes was not formally statistically validated (p=0.17).

Conclusions: We found that WBRT reduced IBTRs among the Luminal A, Luminal B, and the triple negative subgroups, but not in the Her2-positive subgroup. Thus, intrinsic subtyping by IHC may give information on how tumors respond to adjuvant WBRT. Additional studies are required and it remains to study the effect on breast cancer specific survival.

Citation Format: Sjöström M, Lundstedt D, Hartman L, Holmberg E, Kovács A, Malmström P, Niméus E, Werner Rönnerman E, Fernö M, Karlsson P. Relative radioresistency in triple negative tumors in the SweBCG91-RT randomized clinical trial [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P1-09-03.

No breast cancer subgroup can be spared postoperative radiotherapy after breast-conserving surgery. Fifteen-year results from the Swedish Breast Cancer Group randomised trial, SweBCG 91 RT

BACKGROUND

Breast-conserving surgery (BCS) followed by radiotherapy (RT) is an established treatment for women with T1-2N0 breast cancers. Since subgroups of patients have low ipsilateral breast tumour recurrence (IBTR) rates, it is important to study whether RT is necessary for all patients.

PATIENTS AND METHODS

A total of 1187 women with primary T1-2N0M0 breast cancer were randomised, after standardised sector resection, to postoperative whole breast RT or no local treatment. Adjuvant systemic therapy was offered to patients with stage II cancers. Patients were followed with clinical examinations and annual mammography for 10 years and thereafter referred to the Swedish mammography screening program.

RESULTS

After 15 years of follow-up, a higher cumulative incidence of IBTR was observed in control patients, 23.9%, versus irradiated patients, 11.5%, P<0.001. Recurrence-free survival was inferior, 51.7% versus 60.4%, P=0.0013. The main effect of RT was seen during the first 5 years. However, overall survival was not significantly lower 68.4% versus 71.1%, P=0.68, nor was breast cancer-specific mortality significantly higher.

CONCLUSIONS

RT after BCS significantly reduced the incidence of IBTR at 15 years of follow-up. We were unable to identify subgroups which could be spared RT. Breast cancer mortality was not significantly reduced after RT. Good predictive markers for radiation sensitivity and improved adjuvant systemic therapy are needed to omit RT after BCS.

Challenges of evaluating a computer-based educational programme for women diagnosed with early-stage breast cancer: a randomised controlled trial

In a two-group, multi-centre, randomised controlled 9 months trial, we (1) evaluated the impact of a computer-based educational programme compared to standard care and (2) examined whether different patterns of programme usage could be explained by demographic, medical and psychosocial factors. We involved 226 Swedish-speaking women diagnosed with early-stage breast cancer and scheduled for surgery. Primary outcomes were health self-efficacy and health care participation measured by the Comprehensive Health Enhancement Supportive System instrument. Secondary outcomes were anxiety and depression levels measured by the Hospital Anxiety and Depression scale. The Functional Assessment of Cancer Therapy-Breast and Sense of Coherence scales measured psychosocial factors for the study's secondary aim. Multi-level modelling revealed no statistically significant impact of the computer-based educational programme over time on the outcomes. Subsequent exploratory regression analysis revealed that older women with axillary dissection and increased physical well-being were more likely to use the programme. Furthermore, receiving post-operative chemotherapy and increased meaningfulness decreased the likelihood of use. Providing reliable and evidence-based medical and rehabilitation information via a computer-based programme might not be enough to influence multi-dimensional outcomes in women diagnosed with breast cancer. The use of these programmes should be further explored to promote adherence to e-Health supportive interventions.

[Skin biopsy and quantitative sensory testing can contribute to small fibre neuropathy diagnostics]

Nerve conduction studies are normal in small fibre neuropathy and special methods such as skin biopsies or quantitative sensory testing are required for diagnosis. In skin biopsies, nerve fibres are stained immunohistochemically and loss of distal nerve endings can be quantified directly. Assessment of thermal detection thresholds is used to evaluate the function of the sensory thermal pathways, but cannot discriminate between central and peripheral lesions. Small fibre neuropathy is often associated with potentially treatable diseases, and treatment of neuropathic pain may be required.

No clear effect of postoperative radiotherapy on survival of breast cancer patients with one to three positive nodes: a population-based study

BACKGROUND

In published radiotherapy trials, the failure rate in the control arm among patients with one to three positive nodes is high compared with that seen with modern adjuvant treatments. Therefore, the generalizability of the results has been questioned. The aim of the present study was to compare relative survival in breast cancer patients between two Swedish regions with screening mammography programs and adjuvant treatment guidelines similar with the exception of the indication of radiotherapy for patients with one to three positive nodes.

PATIENTS AND METHODS

Between 1989 and 2006, breast cancer patients were managed very similarly in the west and southeast regions, except for indication for postoperative radiotherapy. In patients with one to three positive nodes, postmastectomy radiotherapy was generally given in the southeast region (89% of all cases) and generally not given in the west region (15% of all cases). For patients with one to three positive nodes who underwent breast-conserving surgery, patients in the west region had breast radiotherapy only, while patients in the southeast region had both breast and lymph nodes irradiated.

RESULTS

The 10-year relative survival for patients with one to three positive lymph nodes was 78% in the west region and 77% in the southeast region (P = 0.12). Separate analyses depending on type of surgery, as well as number of examined nodes, also revealed similar relative survival.

CONCLUSION

Locoregional postoperative radiotherapy has well-known side-effects, but in this population-based study, there was little or no influence of this type of radiotherapy on survival when one to three lymph nodes were involved.