Mind over Malignancy: A Systematic Review and Meta-Analysis of Psychological Distress, Coping, and Therapeutic Interventions in Oncology.

Psychological distress is a pervasive yet often undertreated aspect of the cancer experience, contributing to reduced quality of life, poorer treatment adherence, and worse health outcomes. This systematic review and meta-analysis evaluated the efficacy of non-pharmacological, evidence-based psychological interventions on distress, depression, anxiety, coping capacity, and quality of life in adult cancer patients. Interventions were grouped into three domains: structured psychotherapeutic therapies (e.g., Cognitive Behavioral Therapy [CBT], Acceptance and Commitment Therapy [ACT], Meaning-Centered Psychotherapy [MCP]); mindfulness and stress reduction programs (e.g., Mindfulness-Based Stress Reduction [MBSR], Mindfulness-Based Cognitive Therapy [MBCT]); and coping and resilience-enhancing modalities (e.g., Promoting Resilience in Stress Management [PRISM], expressive writing). Following PRISMA guidelines, 42 randomized controlled trials published between 2015 and 2025 were included. A stratified meta-analytic approach calculated pooled standardized mean differences for each intervention class and outcome. Heterogeneity, subgroup, and moderator analyses explored drivers of effect variability. Structured psychotherapeutic interventions yielded the largest effects, especially for depression. Mindfulness-based interventions produced moderate but significant improvements in distress and emotional regulation. Coping and resilience programs provided smaller yet statistically significant gains in adaptive coping. Between-study heterogeneity was moderate, partly explained by intervention type, delivery modality, and cancer subtype. These findings support integrating psychosocial care into standard oncology protocols and endorse its routine implementation as a core component of comprehensive cancer treatment.