Lengacher, C.A., Shelton, M.M., Reich, R.R., Barta, M.K., Johnson-Mallard, V., Moscoso, M.S., . . . Kip, K.E. (2014). Mindfulness based stress reduction (MBSR [BC]) in breast cancer: Evaluating fear of recurrence (FOR) as a mediator of psychological and physical symptoms in a randomized control trial (RCT). Journal of Behavioral Medicine, 37, 185–195. 

To investigate the mechanisms of action of elements of mindfulness-based stress reduction (MBSR) that lead to specific clinical improvements, specifically to postulate and examine how changes in fear of recurrence as a result of participation in MBSR program may mediate a range of positive changes in psychological and physical symptoms and quality of life

At orientation, subjects were consented and randomized, and they completed baseline assessments. The assessments were completed again at two and six weeks following the MBSR program or control period. The program was adapted from the 1990 Jon Kabat-Zinn program. Subjects who were randomized to the MBSR group (n = 40) attended six, weekly, two-hour MBSR sessions with a trained psychologist. Participants learned four meditative practices, sitting meditation, walking meditation, body scan, and yoga, while integrating mindful attention to self-regulate and manage stressful symptoms. Participant materials included a training manual and audio tapes for home practice. Subjects completed a diary daily. Home meditation was advised for 15–45 minutes daily. The usual care (UC) group was offered the MBSR program after the six-week study period.

• N = 82  
• MEAN AGE = 57.2 years (SD = 9.2 years)
• FEMALES: 100%
• KEY DISEASE CHARACTERISTICS: All diagnosed with primary stage 0, I, II, or III breast cancer; completed treatment within the prior 18 months
• OTHER KEY SAMPLE CHARACTERISTICS: Able to read and speak English at an eighth grade level

• SITE: Single-site    
• SETTING TYPE: Outpatient    
• LOCATION: H. Lee Moffitt Cancer Center, Tampa, FL

• PHASE OF CARE: Transition phase after active treatment
• APPLICATIONS: Elder care  

This was a randomized, controlled trial. Subjects were randomly assigned in a one-to-one ratio to either the MBSR or UC group. Randomization was stratified in an unblocked manner. Study personnel were blinded initially.

• To assess fear of recurrence as a potential mediator of the effects of MBSR, an analysis was conducted using six outcome measures in which MBSR demonstrated evidence of efficacy. These were perceived stress, depressive symptoms, state anxiety, trait anxiety, and aggregate mental and physical health.
• A 30-item Concerns about Recurrence Scale (CRS) was used.
• State and trait anxiety was measured by State-Trait Anxiety Inventory (STAI)
• Depression was measured by the Center for Epidemiological Studies Depression Scale (CES-D)
• Optimism was measure by the Life Orientation Test-Revised (LOT-R).
• Perceived stress was measure by the Perceived Stress Scale (PSS)
• Quality of life was measured by the Medical Outcomes Studies Short-Form General Health Survey (MOS SF-36) 
• Social Support was measured by the Medical Outcomes Study (MOS) Social Support Survey

From baseline to six-weeks, the MBSR group experience more favorable changes than the UC group for several potential mediators including fear of recurrence concerns (2.8 versus .2, p = .007); fear of recurrence problems (11.4 versus .2, p = .02); depression (7.2 versus 4, p = .04); physical functioning (3.8 versus .5, p = .01) and energy (8.8 versus 5, p = .07). After removing direct effects of MBSR on outcomes of interest, the strongest and most consistent evidence for mediating effects (how MBSR works) was for change in fear of recurrence problems and change in physical functioning. The results indicate that MBSR is associated with reduced fear of recurrence and improved physical functioning which in turn are associated with reduced perceived stress and state and trait anxiety. The women in the UC group who experienced reduced fear of recurrence and improved physical functioning by mechanisms other than MBSR also experienced significantly reduced perceived stress and anxiety. Both groups experienced reduced anxiety and depression over time. There were no significant differences in anxiety between groups. Postintervention, the MBSR group had significantly higher depression scores (p = .04).

The fear of recurrence is highly prevalent in breast cancer survivors and is associated with considerable psychological distress. The results of this study may indicate that one of the mechanisms for how MBSR (BC) works is through the cognitive process of self-regulation of fear of recurrence to improve stress, anxiety, and physical functioning. The fear of recurrence influence by MBSR (BC) appeared to be reliable and clinically relevant. The findings did not demonstrate a direct effect on anxiety or depression scores.

• Small sample (< 100)
• Baseline sample/group differences of import
• Risk of bias (sample characteristics)
• Findings not generalizable
• Intervention expensive, impractical, or training needs
• Other limitations/explanation: Trained psychologist and expensive intervention; included only early-stage breast cancer survivors; limited to short-term effects; symptoms at baseline were low for both groups, indicating a potential floor effect with little room for improvement

The findings of this study show a clustering of multiple symptoms among breast cancer survivors. Interventions to simultaneously address multiple symptoms should be studied. MBSR is supported as being beneficial in reducing fear of recurrence and improving physical functioning. Training programs and awareness for nurses and staff members should be supported in cancer centers and survivorship programs.