Psychosocial characteristics of chronic pain in cancer survivors referred to an Australian multidisciplinary pain clinic

Objective: To describe the clinical and psychosocial characteristics of chronic pain in cancer survivors referred to one Australian hospital's ambulatory pain clinic over a 7-year period (2013-19), and to compare cancer treatment-related pain with comorbid non-malignant pain.

Method: Retrospective chart review including responses to standardized self-report questionnaires (Brief Pain Inventory, Depression Anxiety Stress Scale, Pain Self-Efficacy Questionnaire, Pain Catastrophizing Scale), routinely collected in all patients referred to pain clinics at Australian and New Zealand hospitals.

Results: Of 3510 new referrals during the study period, 267 (7.5%) had a history of cancer and 176 (5.0%) met the study's eligibility criteria. Their average age was 63 ± 13 years, with 55% female. Breast cancer survivors were commonest, followed by hematological, prostate, melanoma, and colorectal, a median of 3 years post-diagnosis. Pain was attributed to cancer treatment in 87 (49%), surgery being the commonest modality. Multimodal treatment (n = 89, 58%) was significantly commoner in the treatment-related pain group (p < 0.001). Average pain severity was moderate, as was pain-related disability and distress. Pain cognitions were often maladaptive (low pain self-efficacy, high pain catastrophizing), predicted by pre-existing anxiety and depression. Associations between pain cognitions and outcomes were medium-to-large. Differences between treatment pain and comorbid pain were small-to-medium. Their scores were similar to Australian pain clinic norms.

Conclusion: Cancer treatment causes tissue damage, but pain-related distress and disability in survivors is associated with maladaptive pain cognitions. Survivors with poor pain outcomes should be evaluated for unhelpful thoughts and beliefs especially when they have pre-existing depression or anxiety.