MS-N185 · Psychological and mind–body support · Appraised October 30, 2026

Acceptance and commitment therapy for fear of progression during breast-cancer particle therapy

Aliases: ACT

Evidence at a glance

Question: Can group acceptance and commitment therapy reduce fear of progression during particle therapy for breast cancer?
Finding: A 108-participant single-center randomized trial reported lower fear-of-progression and psychological-distress scores through three months. The usual-care control did not match therapist attention or group support.
Evidence label: Positive short-term randomized signal
Benefit: Reduced self-reported fear of progression and psychological distress.
Certainty: Low to moderate. Intention-to-treat and sensitivity analyses were reassuring, but the setting was narrow and the comparator did not control for attention.
Risk: No intervention-related adverse events were identified, but clinical deterioration and treatment changes were not systematically collected as safety outcomes.
Cancer-control boundary: Reducing fear of progression does not reduce the biological risk of progression and is not evidence of tumor control.

Study details

Intervention: Five group sessions, 90–120 minutes each over 2.5 weeks, covering acceptance, cognitive defusion, present-moment awareness, values and committed action.
Population: Adults aged 20–59 with breast cancer, elevated fear-of-progression scores and ongoing proton or heavy-ion therapy at one Shanghai hospital.
Design and comparator: Parallel randomized controlled trial; ACT plus usual care versus usual care alone.
Sample and follow-up: 108 randomized, 54 per group; 95 completed three months; overall attrition 12%.
Primary outcome: Fear of Progression Questionnaire–Short Form.
Results: Fear of progression favored ACT at immediate, one-month and three-month assessments (all P<.001). Psychological distress also favored ACT; psychological flexibility differed only at three months (P=.037).
Negative and uncertain findings: No attention-matched control; numerical between-group effects and confidence intervals were not summarized in the abstract; long-term durability is unknown.
Funding and conflicts: Shanghai Shenkang Hospital Development Center and Fudan University–Fosun Nursing Research Fund; authors reported no commercial or financial conflict.

Practical safety context

ACT should complement—not replace—clear oncologic information, symptom assessment and mental-health care. Severe anxiety, depression, trauma symptoms or suicidal thoughts need appropriate clinical evaluation.

Questions for the care team

Is fear being driven by unanswered medical questions or untreated symptoms?
Is the group facilitator trained to recognize severe distress?
How will improvement be measured beyond the three-month study window?

Primary sources

Last literature search: October 30, 2026 · Record appraisal: October 30, 2026

Educational evidence summary, not medical advice. Do not change cancer treatment or supportive medications without discussing the decision with the treating team.