Beutler, Andreas S.

Chemotherapy-induced peripheral neuropathy (CIPN) is a common and potentially permanent adverse effect of chemotherapeutic agents including taxanes such as paclitaxel and platinum-based compounds such as oxaliplatin and carboplatin. Previous studies have suggested that genetics may impact the risk of CIPN. We conducted genome-wide association studies (GWASs) for CIPN in two independent populations who had completed European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ)-CIPN20 assessments (a CIPN-specific 20-item questionnaire which includes three scales that evaluate sensory, autonomic, and motor symptoms). The study population N08Cx included 692 participants from three clinical trials (North Central Cancer Treatment Group (NCCTG) N08C1, N08CA, and N08CB) who had been treated with paclitaxel, paclitaxel plus carboplatin, or oxaliplatin. The primary endpoint for the GWAS was the change from pre-chemotherapy CIPN20 sensory score to the worse score over the following 18 weeks. Study population The Mayo Clinic Breast Disease Registry (MCBDR) consisted of 381 Mayo Clinic Breast Disease Registry enrollees who had been treated with taxane or platinum-based chemotherapy. The primary endpoint for the GWAS assessed was the earliest CIPN20 sensory score available after the completion of chemotherapy. In multivariate model analyses, chemotherapy regimen (p = 3.0 × 10−8) and genetic ancestry (p = 0.007) were significantly associated with CIPN in the N08Cx population. Only age (p = 0.0004) was significantly associated with CIPN in the MCBDR population. The SNP most associated with CIPN was rs56360211 near PDE6C (p =7.92 × 10−8) in N08Cx and rs113807868 near TMEM150C in the MCBDR (p = 1.27 × 10−8). Due to a lack of replication, we cannot conclude that we identified any genetic predictors of CIPN.

Health-related quality of life (HRQOL) is an important prognostic patient-reported outcome in oncology. Because prior studies suggest that HRQOL is, in part, heritable, we performed a GWAS to elucidate genetic factors associated with HRQOL in breast cancer survivors. Physical and mental HRQOL were measured via paper surveys that included the PROMIS-10 physical and mental health domain scales in 1442 breast cancer survivors participating in the Mayo Clinic Breast Disease Registry (MCBDR). In multivariable regression analyses, age and financial concerns were significantly associated with global physical health (age: p = 1.6 × 10−23; financial concerns: p = 4.8 × 10−40) and mental health (age: p = 3.5 × 10−7; financial concerns: p = 2.0 × 10−69). Chemotherapy was associated with worse global mental health (p = 0.01). In the GWAS, none of the SNPs reached the genome-wide association significance threshold of 5 × 10−8 for associations with either global physical or global mental health, however, a cluster of SNPs in SCN10A, particularly rs112718371, appeared to be linked to worse global physical health (p = 5.21 × 10−8). Additionally, SNPs in LMX1B, SGCD, PARP12 and SEMA5A were also moderately associated with worse physical and mental health (p < 10−6). These biologically plausible candidate SNPs warrant further study as possible predictors of HRQOL.

Knee osteoarthritis is one of the most common causes of chronic pain worldwide, and several animal models have been developed to investigate disease mechanisms and treatments to combat associated morbidities. Here we describe a novel method for assessment of locomotor pain behavior in Yucatan swine. We used monosodium iodoacetate (MIA) to induce osteoarthritis in the hindlimb knee, and then conducted live observation, quantitative gait analysis, and quantitative weight-bearing stance analysis. We used these methods to test the hypothesis that locomotor pain behaviors after osteoarthritis induction would be detected by multiparameter quantitation for at least 12 wk in a novel large animal model of osteoarthritis. MIA-induced knee osteoarthritis produced lameness quantifiable by all measurement techniques, with onset at 2 to 4 wk and persistence until the conclusion of the study at 12 wk. Both live observation and gait analysis of kinetic parameters identified mild and moderate osteoarthritis phenotypes corresponding to a binary dose relationship. Quantitative stance analysis demonstrated the greatest sensitivity, discriminating between mild osteoarthritis states induced by 1.2 and 4.0 mg MIA, with stability of expression for as long as 12 wk. The multiparameter quantitation used in our study allowed rejection of the null hypothesis. This large animal model of quantitative locomotor pain resulting from MIA-induced osteoarthritis may support the assessment of new analgesic strategies for human knee osteoarthritis.

AimsChemotherapy‐induced peripheral neuropathy (PN) is a treatment limiting toxicity of paclitaxel. We evaluated if EPHA genetic variation (EPHA4, EPHA5, EPHA6, and EPHA8) is associated with PN sensitivity by accounting for variability in systemic paclitaxel exposure (time above threshold).MethodsGermline DNA from 60 patients with breast cancer was sequenced. PN was measured using the 8‐item sensory subscale (CIPN8) of the patient‐reported CIPN20. Associations for 3 genetic models were tested by incorporating genetics into previously published PN prediction models integrating measured paclitaxel exposure and cumulative treatment. Significant associations were then tested for association with PN‐related treatment disruption.ResultsEPHA5 rs7349683 (minor allele frequency = 0.32) was associated with increased PN sensitivity (β‐coefficient = 0.39, 95% confidence interval 0.11–0.67, p = 0.007). Setting a maximum tolerable threshold of CIPN8 = 30, optimal paclitaxel exposure target is shorter for rs7349683 homozygous (11.6 h) than heterozygous (12.6 h) or wild‐type (13.6 h) patients. Total number of missense variants (median = 0, range 0–2) was associated with decreased PN sensitivity (β‐coefficient: −0.42, 95% confidence interval −0.72 to −0.12, P = .006). No association with treatment disruption was detected for the total number of missense variants or rs7349683.ConclusionIsolating toxicity sensitivity by accounting for exposure is a novel approach, and rs7349683 represents a promising marker for PN sensitivity that may be used to individualize paclitaxel treatment.

532 Background: Chemotherapy induced peripheral neuropathy (CIPN) is a common, debilitating paclitaxel side effect that has been primarily attributed to cumulative systemic paclitaxel exposure. Paclitaxel dose-adjustment to achieve target systemic exposure decreases but does not eliminate severe CIPN, suggesting some patients are inherently CIPN-sensitive. Ephrin ( EPHA) polymorphisms have been reported to increase CIPN occurrence (Baldwin 2012, Leandro-Garcia 2013, Boora 2016) but replication has been challenging, perhaps due to the inability to isolate CIPN-sensitivity by accounting for systemic exposure differences. The study purpose was to determine if EPHA genetic variants previously associated with CIPN occurrence are associated with CIPN-sensitivity. Methods: PN was assessed at baseline and weekly using the 8-item sensory subscale (CIPN8) of the patient-reported EORTC CIPN20 in patients receiving paclitaxel 80 mg/m2 weekly x 12. EPHA4, EPHA5, EPHA6, and EPHA8 were sequenced in germline DNA. Associations with higher PN-sensitivity were tested for three genetic models (total variants, coding variants, and rs7349683) by incorporating genetics into previously published CIPN8 predictive models that included measured paclitaxel exposure. Significant associations were tested for association with higher risk of PN-related treatment disruption (i.e. dose decrease, delay, or discontinuation). Results: In the 59 included patients, carrying EPHA5 rs7349683 was associated with greater CIPN sensitivity (beta coefficient: 0.40, standard error: 0.14, p = 0.005), indicating these patients had a greater increase in CIPN8 during treatment than would be predicted based on cumulative paclitaxel exposure. Rs7349683 was not associated with increased PN-induced treatment disruption, perhaps due to the low number of events (n = 19). Conclusions: Using a novel approach that isolates CIPN-sensitivity by accounting for measured paclitaxel exposure, our results provide further evidence that EPHA5 rs7349683 may be a promising marker for CIPN. If additional validation studies confirm this association, genetic testing could enable personalized treatment strategies to prevent CIPN in patients with breast cancer.