This study will focus on supporting cancer patients who often experience emotional challenges like anxiety and depression. It will test a two-week online program called Acceptance and Commitment Therapy (ACT), designed to help people manage difficult emotions and focus on what matters most in their lives.

The program will include short, easy-to-follow sessions covering helpful strategies like accepting distress and staying present in the moment. Participants will be randomly assigned to either join the ACT program or wait for the program while continuing their usual care. The study aims to determine whether the ACT program can reduce psychological distress, anxiety, and depression in cancer patients. The study will use a mixed-methods approach, combining both quantitative data (such as changes in distress, anxiety, and depression) and qualitative insights from participant interviews. This will help us gain a deeper understanding of how the ACT program may support the psychological distress of cancer patients.

Inclusion Criteria:

• age 18 and above;
• diagnosed cancer with a clear disease course
• fluent in Chinese with the ability to read and understand questionnaires independently;
• ability to operate a smartphone independently;
• not participating in or intervening in other clinical studies.

Exclusion Criteria:

• younger than 18 years of age
• unable to use a smartphone
• have significant cognitive impairment or a serious systemic disease or psychiatric disorder
• concurrently participating in other clinical studies or undergoing other psychotherapy