Abstract: Twenty-eight randomised controlled trials comprising 3940 participants were included. The most frequent reasons for exclusion were non-randomised trials and the inclusion of women with metastatic disease. A wide range of interventions were evaluated, with 24 trials investigating a cognitive behavioural therapy and four trials investigating psychotherapy compared to control. Pooled standardised mean differences (SMD) from baseline indicated less depression (SMD -1.01, 95% confidence interval (CI) -1.83 to -0.18; P = 0.02; 7 studies, 637 participants, I2 = 95%, low quality evidence), anxiety (SMD -0.48, 95% CI -0.76 to -0.21; P = 0.0006; 8 studies, 776 participants, I2 = 64%, low quality evidence) and mood disturbance (SMD -0.28, 95% CI -0.43 to -0.13; P = 0.0003; 8 studies, 1536 participants, I2 = 47%, moderate quality evidence) for the cognitive behavioural therapy group than the control group. For quality of life, only an individually-delivered cognitive behavioural intervention showed significantly better quality of life than the control with an SMD of 0.65 (95% CI 0.07 to 1.23; P = 0.03; 3 studies, 141 participants, I2 = 41%, very low quality evidence). Pooled data from two group-delivered studies showed a non-significant overall survival benefit favouring cognitive behavioural therapy compared to control (pooled hazard ratio (HR) 0.76, 95% CI 0.25 to 2.32; P = 0.63; 530 participants, I2 = 84%, low quality evidence). Four studies compared psychotherapy to control with one to two studies reporting on each outcome. The four studies were assessed as high risk of bias and provided limited evidence of the efficacy of psychotherapy. Adverse events were not reported in any of the included studies. A psychological intervention, namely cognitive behavioural therapy, produced favourable effects on some psychological outcomes, in particular anxiety, depression and mood disturbance. However, the evidence for survival improvement is still lacking. These findings are open to criticism because of the notable heterogeneity across the included studies and the shortcomings of the included studies.

Plain-language summary: The evidence was current to May 2013. An intervention could be delivered in a group setting (group intervention), as one to one contact between a therapist and a patient (individual intervention) or in the form of couple therapy where the patient and her spouse attends the therapy sessions (couple intervention). The control group could receive educational leaflets or have access to seminars or relaxation classes. A comprehensive search of the literature was conducted and 28 studies comprising 3940 participants were included. The majority (24 out of 28 studies) of interventions were based on cognitive behavioural therapy, which involves changing a person's thoughts and behaviour. Four studies used psychotherapy as the intervention. Generally, the methods for assessing outcomes (such as anxiety, depression, quality of life) after the intervention and the timing of these assessments were not uniform across studies. Women who received cognitive behavioural therapy showed important reductions in anxiety, depression and mood disturbance, especially when it was delivered to groups of women. An improvement in quality of life was observed when women received individual cognitive behavioural therapy compared to the control group. The effects on survival were uncertain because the results were imprecise. The four psychotherapy studies reported limited information for each outcome. Therefore no firm conclusion could be made about the efficacy of psychotherapy. Adverse events were not reported in any of the included studies. Further research should aim to provide evidence for people to make informed decisions about whether the effects of these treatments are sustainable after discontinuation of the therapy. The quality of evidence ranged from very low quality (for example for quality of life, individually delivered intervention) to moderate quality evidence (for mood disturbance). The interventions varied between studies as did the methods and timing of outcome measures and treatment received within the control groups.