Purpose: ConquerFear is an efficacious intervention for fear of cancer recurrence (FCR) that demonstrated greater improvements than an attention control (relaxation training) in a randomized controlled trial. This study aimed to determine mediators and moderators of the relative treatment efficacy of ConquerFear versus relaxation.
Methods: One hundred and fifty-two cancer survivors completed 5 therapy sessions and outcome measures before and after intervention and at 6 months' follow-up. We examined theoretically relevant variables as potential mediators and moderators of treatment outcome. We hypothesized that metacognitions and intrusions would moderate and mediate the relationship between treatment group and FCR level at follow-up.
Results: Only total FCR score at baseline moderated treatment outcome. Participants with higher levels of FCR benefited more from ConquerFear relative to relaxation on the primary outcome. Changes in metacognitions and intrusive thoughts about cancer during treatment partially mediated the relationship between treatment group and FCR.
Conclusions: These results show that ConquerFear is relatively more effective than relaxation for those with overall higher levels of FCR. The mediation analyses confirmed that the most likely mechanism of treatment efficacy was the reduction in unhelpful metacognitions and intrusive thoughts during treatment, consistent with the theoretical framework underpinning ConquerFear.
Implications for cancer survivors: ConquerFear is a brief, effective treatment for FCR in cancer survivors with early-stage disease. The treatment works by reducing intrusive thoughts about cancer and changing beliefs about worry and is particularly helpful for people with moderate to severe FCR.
Keywords: Acceptance commitment therapy; Cancer; Fear of recurrence; Intrusive thoughts; Metacognitions; Metacognitive therapy; Oncology; Psychotherapy.