Patel, Diya

Introduction: The Mindfulness-Based Stress Reduction program for breast cancer survivors (MBSR [BCs]) is a stress-reducing program designed to increase cognitive functioning through four meditational practices. This randomized clinical trial aimed to determine if improvements in cognitive functioning and perceived cognitive abilities achieved from the MBSR(BC) were mediated through increased mindfulness, decreased rumination, and decreased perceived stress. Methods: Breast cancer survivors (BCSs) who met inclusion criteria of stage I, II, or III BC and received either chemotherapy (CT) or both CT and radiation were randomized to either the 6-week MBSR(BC), or Breast Cancer Education Support (BCES) program, or to a usual care (UC) regimen. Analysis of covariance was first implemented to identify potential mediators, followed by a formal mediational analysis to evaluate the effects of MBSR(BC) on 6-, 12-, and 26-week outcomes. Results: After consent, 212 BCS were randomized to MBSR(BC) ( n = 91), BCES ( n = 90), or UC ( n = 31). The mean age was 56.5 and the majority of the BCS, 73.1%, were White and non-Hispanic. Results showed increases in “observing” as part of mindfulness as a potential mediator of MBSR(BC) effects on impairments on quality of life and logical memory at 6 months relative to UC. No mediation effects were identified for outcomes measured at 6 or 12 weeks and also when MBSR(BC) was compared with the BCES program. Discussion: These results partially supported our hypothesis that improvement in cognitive functioning would occur through increased mindfulness. Although few mediating relationships were identified, results showed a relationship between mindfulness and cognitive functioning. Both mediating relationships occurred through increases in “observing,” a subconcept of “mindfulness,” when compared to the MBSR(BC) with UC at 6 months. This study shows that mediators may help “optimize” clinical therapeutic treatment effects, thus contributing to the advancement of science. Trial Registration: ClinicalTrials.gov, www.ClinicalTrials.gov . Registration Number: NCT02786797.

Background Genetics may influence symptoms experienced by breast cancer survivors (BCS) by moderating the effects of stress-reducing interventions, including the Mindfulness-Based Stress Reduction (MBSR(BC)) program, to reduce symptom severity. As part of a larger clinical trial, the aim of this study was to evaluate genetic variants as moderators of MBSR(BC) on improvements among BCS in cognitive functioning and symptoms. Methods BCS ( n = 128) were randomized to MBSR(BC) or the Breast Cancer Education Support Program. Objective neuropsychological and subjective measures of cognitive performance, and psychological and physical symptoms were collected at baseline, 6, 12, and 26 weeks. Linear mixed models were implemented to identify MBSR(BC)’s effects over time. A total of 22 single nucleotide polymorphisms (SNPs) from 20 genes known to be related to these symptoms were investigated using genomic DNA. These SNPs were tested as moderators of MBSR(BC) program effects. Results Results showed MBSR(BC) participants experienced significantly greater benefits in cognitive functioning, however, the level of benefit varied based on one’s genetic profile. Effects sizes, consistency across similar measures were investigated. Among 22 candidate SNPs, rs4680 in COMT, rs1800497 in ANKK1, and rs6277 in DRD2 demonstrated the strongest, most consistent positive effects in moderating MBSR(BC)’s impact on cognitive outcomes. Conclusions Although the effects were small, this translational research may potentially identify BCS with genotypes that would be most influenced by the MBSR(BC) program. These results may be used to develop personalized intervention programs tailored to the genetic profile of each breast cancer survivor who received chemotherapy or chemotherapy and radiation. Trial Registration ClinicalTrials.gov, https://www.ClinicalTrials.gov Registration Number: NCT02786797.