Understanding mediation effect of cancer-related rumination between physical symptom distress and psychological distress in Chinese Colorectal Cancer Patients

Abstract

BACKGROUND: The age-adjusted incidence of colorectal cancer has increased over the past decade both globally and locally. Physical symptoms distress is known to be an important contributor to psychological distress among cancer patients. In addition, intrusive thoughts are associated with the onset of depression and anxiety. This study aims to examine the possible mediation role of cancerrelated rumination between physical symptom distress and depression and anxiety among Chinese Colorectal cancer patients across the cancer journey. METHOD: Newly diagnosed colorectal cancer (CRC) patients recruited from a Hong Kong teaching hospital were interviewed three times: 1 day before surgery (T1), 1 month (T2) and 4 months post-surgery (T3) respectively. Patient’s anxiety and depression (psychological distress), physical symptom distress, cancer-related rumina-tion and demographic information were recorded at each of three interviews. Linear Mixed Modelling was adopted to investigate if there was any mediation effect from rumination. RESULTS: Overall, 205/219 (93.6%) patients participated in this study. Anxiety (b = 0.41, SE = 0.12, p = 0.001), but not depression (b = 0.11, SE = 0.13, p = 0.395) levels declined significantly from pre-surgery to 4 months post-surgery. Physical symptom distress was positively related to both anxiety level (b = 2.35, SE = 0.37, p < 0.001) and depression level (b = 2.80, SE = 0.47, p < 0.001) respectively. In addition, higher physical symptom distress was associated with stronger rumination (b = 0.408, SE = 0.46, p < 0.001). Sobel test suggested a significant mediation effect from rumination between physical symptom distress and anxiety (z = 7.19, p < 0.001) and depression (z = 5.84, p < 0.001). CONCLUSIONS: CRC patients had decreasing anxiety level but maintained fairly stable levels of depression over the time from pre-surgery to 4 months post-surgery. Cancer-related rumination seems to carry some of the impact associated with physical symptom distress on cancer patients’ anxiety and depression level. There was a partially mediation effect of cancer-related rumination on the relationship between physical symptom distress and psychological morbidity. This points to the meanings and/or disruption attributed to physical symptoms as potential therapeutic targets. RESEARCH IMPLICATIONS: This study revealed the pattern change on psychological distress (depression and anxiety) across the period from pre-surgery to 4 months post-surgery among CRC patients as well as rumination partially affected the relationship between physical symptom distress and depression and anxiety. Further investigation may be needed to reveal if the relationship between physical symptom distress and prolonged psychological distress (e.g. 1 year post-surgery) would also be mediated by rumination. CLINICAL IMPLICATIONS: Health care providers need to pay more attention to patients’ physical symptoms. Distress arising from physical symptoms appears to be in response to either the potential meanings attributed to those symptoms, or to the disruptive effect of these symptoms on daily life, preventing ‘forgetting about’ cancer that is necessary for return to near normal life. Interventions should address either physical symptoms themselves or ruminative thinking about cancer prompted by these to minimize psychological morbidities. ACKNOWLEDGEMENT OF FUNDING: This project was funded by The Health and Health Service Research Fund of the Hong Kong Government, grant number 0708651.