Rodriguez, Carmen S.

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.

Introduction: The Mindfulness-Based Stress Reduction (MBSR) Program for breast cancer survivors (BCS) is designed to enhance cognitive training through formal and informal meditational practices. This randomized clinical trial (RCT) aimed to evaluate if BCS assigned to either the MBSR(BC), Breast Cancer Education Support (BCES), or Usual Care (UC) regimens experienced greater improvements at 6, 12, and 26 weeks on objective and subjective cognitive performance. Methods: BCS ( n = 212) randomized to a three-group RCT: MBSR(BC) ( n = 91), BCES ( n = 90), or UC ( n = 31) were assessed on cognitive performance and symptoms at baseline, 6, 12, and 26 weeks. Linear mixed models were fit to evaluate the effects of the MBSR(BC) program, hypothesizing ordered effect improvements: (MBSR[BC] highest, BCES intermediate, UC lowest) along with baseline characteristics evaluated as moderators. Results: Of the BCS (mean age of 57), 73% were White, and non-Hispanic, and 77% received both chemotherapy (CT) and radiation. Cognitive performance improved in all groups. Although there were no statistically significant between-group differences in cognitive outcomes, significant symptom reductions occurred for the MBSR(BC) group ( p = 0.003). Within-group effect size analysis at 26 weeks showed substantial improvements in all three groups (effect sizes >0.50) in subjective impairments and quality of life (effect size >0.50) and objective measures of cognitive performance. MBSR(BC) showed the largest within-group effect size in the reduction of fatigue (effect size = 0.81). Effect sizes occurred in the hypothesized direction for 10 of the 18 outcomes. Discussion: Although the MBSR(BC) program did not show significant differences in cognitive performance compared with BCES and UC, all groups improved and reductions in fatigue were beneficial for MBSR(BC). Results suggest that cognitive performance may improve after CT over time considering one’s natural history. Furthermore, BCS enrolled in RCTs may be more motivated to improve their health status (NCT02786797).