Hülür, Gizem

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.

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).