Mindfulness and Sex Education for Sexual Dysfunction in Breast Cancer Survivors: Mediators and Moderators of Treatment Outcome.

Mindfulness-based cognitive therapy (MBCT) and supportive-expressive sex education therapy (STEP) are effective group treatments for sexual dysfunction after breast cancer (BrCa). We explored mediators and moderators of outcomes following the 8-week groups. BrCa survivors (n = 116, mean age = 49.9 ± 9.5) were randomized to group and completed measures before, immediately after, and 6 months after treatment. Mediators assessed were changes in depression, chronic pain acceptance, pain catastrophizing, and trait mindfulness. Potential moderators included age, treatment expectations, baseline mental health, cancer treatment duration, use of chemotherapy, and adjuvant endocrine therapy. Longitudinal mediation and moderation were assessed using linear mixed models. Increases in pain acceptance mediated improvements in sexual desire and reductions in both sexual distress and vaginal pain. Decreases in pain catastrophizing mediated improvements in sexual distress. Higher expectations for treatment led to greater reductions in sexual distress. Those with low baseline anxiety showed greater improvements in desire and distress. Low baseline depression predicted greater improvements in desire, but only in the STEP arm. Older STEP participants improved significantly more than younger STEP participants. Cancer-related treatment variables, and the impact of adjuvant endocrine therapy, had differential effects on outcomes based on the treatment arm of the study. In conclusion, treatments aimed at improving pain acceptance and pain catastrophizing are likely to promote improvements in sexual health among BrCa survivors, and factoring in patients' expectations about treatment improvements, depression and anxiety, age, duration of cancer treatment, chemotherapy, and adjuvant hormonal therapy may help to guide treatment recommendations for sexual dysfunction.