Background and aims: Chemotherapy-induced peripheral neuropathy (CIPN) can be a severely disabling side-effect of commonly used cancer chemotherapeutics, requiring cessation or dose reduction, impacting on survival and quality of life. Our aim was to conduct a systematic review and meta-analysis of research using animal models of CIPN to inform robust experimental design. Methods: We systematically searched 5 online databases (PubMed, Web of Science, Citation Index, Biosis Previews and Embase (September 2012) to identify publications reporting in vivo CIPN modelling. Due to the number of publications and high accrual rate of new studies, we ran an updated search November 2015, using machine-learning and text mining to identify relevant studies. All data were abstracted by two independent reviewers. For each comparison we calculated a standardised mean difference effect size then combined effects in a random effects metaanalysis. The impact of study design factors and reporting of measures to reduce the risk of bias was assessed. We ran power analysis for the most commonly reported behavioural tests. Results: 341 publications were included. The majority (84%) of studies reported using male animals to model CIPN; the most commonly reported strain was Sprague Dawley rat. In modelling experiments, Vincristine was associated with the greatest increase in pain-related behaviour (-3.22 SD [-3.88; -2.56], n=152, p=0). The most commonly reported outcome measure was evoked limb withdrawal to mechanical monofilaments. Pain-related complex behaviours were rarely reported. The number of animals required to obtain 80% power with a significance level of 0.05 varied substantially across behavioural tests. Overall, studies were at moderate risk of bias, with modest reporting of measures to reduce the risk of bias. Conclusions: Here we provide a comprehensive summary of the field of animal models of CIPN and inform robust experimental design by highlighting measures to increase the internal and external validity of studies using animal models of CIPN. Power calculations and other factors, such as clinical relevance, should inform the choice of outcome measure in study design.

Chronic pain strategies must be embedded within broader efforts to tackle deprivation

ABSTRACTBackgroundCommon types of musculoskeletal conditions include pain in the neck and shoulder areas. This study seeks to identify the genetic variants associated with neck or shoulder pain based on a genome-wide association approach using 203,309 subjects from the UK Biobank cohort and look for replication evidence from the Generation Scotland: Scottish Family Health Study (GS:SFHS) and TwinsUK.MethodsCases in the UK Biobank were determined by a question which asked the participants if they had experienced pain in the neck or shoulder in the previous month influencing daily activities. Controls were the UK Biobank participants who reported no pain anywhere in the last month. A genome-wide association study was performed adjusting for age, sex, BMI and 9 population principal components. Significant and independent genetic variants were then sent to GS:SFHS and TwinsUK for replication.ResultsWe identified 3 genetic loci that were associated with neck or shoulder pain in the UK Biobank samples. The most significant locus was in an intergenic region in chromosome 17, rs12453010, having P = 1.66 × 10-11. The second most significant locus was located in the FOXP2 gene in chromosome 7 with P = 2.38 × 10-10 for rs34291892. The third locus was located in the LINC01572 gene in chromosome 16 with P = 4.50 × 10-8 for rs62053992. In the replication stage, among 4 significant and independent genetic variants, rs2049604 in the FOXP2 gene and rs62053992 in the LINC01572 gene were weakly replicated in GS:SFHS (P = 0.0240 and P = 0.0202, respectively). None of the single nucleotide polymorphisms (SNPs) were replicated in the TwinsUK cohort (P > 0.05).ConclusionsWe have identified 3 loci associated with neck or shoulder pain in the UK Biobank cohort, two of which were weakly supported in a replication cohort. Further evidence is needed to confirm their roles in neck or shoulder pain.SignificanceThis is the first genome-wide association study on neck or shoulder pain. We have identified 3 genetic loci (an intergenic region in chromosome 17, the FOXP2 gene in chromosome 7, and the LINC01572 gene in chromosome 16) that are associated with neck or shoulder pain using the UK Biobank cohort, among which the FOXP2 gene and the LINC01572 gene were weakly replicated by the Generation Scotland: Scottish Family Health Study (P < 0.05). The SNP heritability was 0.11, indicating neck or shoulder pain is a heritable trait. The tissue expression analysis suggested that neck or shoulder pain was related to multiple brain tissues, indicating the involvement of neuron function. The results will inform further research in the characterisation of the mechanisms of neck or shoulder pain.

Introduction Although pain and depression co-exist in 36.5% of cancer patients, the precise nature of the relationship between these symptoms requires elucidation. This study aimed to further understanding of the relationship by determining whether improved pain is associated with a significant reduction in depression and increased quality of life in cancer patients. Methods A secondary data analysis of patients enrolled in pain intervention studies (n=123) was undertaken. Pain, depression and quality of life were measured at baseline and endpoint using the Brief Pain Index (BPI), Hospital and Anxiety and Depression Score (HADS) and EuroQol Thermometer assessment tools respectively. The Mann-Whitney U-test and Fisher's Exact Test were used to statistically analyse score differences between pain response groups. Results Baseline BPI, HADS and EuroQol scores were well matched between the groups. Patients responding to pain interventions had an average 2.95 point decrease in endpoint HADS scores, contrasting with a 0.89 increase in non-responding patients (score range 0–42). There was a statically significant difference in the endpoint total HADS scores between the two groups (p=0.0015). Similar mean changes in EuroQol scores revealed increased quality of life scores occurring in patients with (10.64) and without (12.41) improved pain. Conclusions Improving pain results in reduced depression scores. This supports a unidirectional relationship between pain and depression. Further study is required to establish the presence of a bidirectional relationship. Understanding the relationship between pain and depression allows prioritisation of targeted management of co-existent pain and depression, which may improve the clinical care of cancer patients.