Understanding pain in malignant mesothelioma: a prospective, longitudinal cohort study

Pain associated with malignant mesothelioma can be complex. The natural course of pain over the disease trajectory is not well studied. The aim of this study was to explore the prevalence, severity, impact and clinical course of pain for people with mesothelioma over a 12-month period.

A prospective observational study was conducted as a component of a larger national, multi-centre cohort study on mesothelioma - ASSESS-meso (A prospective obServational cohort Study collecting data on dEmographics, Symptoms and biomarkerS in people with mesothelioma) (ISRCTN: 61,861,764). Adults (> = 18 years) newly diagnosed with mesothelioma were recruited from out-patient clinics in 20 hospitals. Baseline demographic and clinical data were recorded. Frequency, severity and impact of pain, quality of life and mood were collected using Patient-Reported Outcome Measures (e.g., EORTC Quality of Life Questionnaire Core Questionnaire PALliative Cancer [QLQ-C15-PAL], Brief Pain Inventory [BPI]). Follow-up occurred 3-monthly for 12-months.

Among the 150 participants recruited, mean age was 72.4 years (SD 8.1), with 112 (74.7%) being men. Baseline assessments showed a greater proportion of participants were affected by dyspnoea compared with pain. Overall, twenty-one (14.0%) participants reported moderate or severe chest pain (defined as > = 40/100) although none were receiving strong opioids. Median pain duration was 14.1 weeks (IQR 10-24.1). At 9-12 months, quality of life was poorer in those reporting moderate or severe pain (mean overall QLQ-C15-PAL score 41.7 [SD = 20.4] vs. 71.6 [SD = 19.5]) and this pain interfered more with daily activities (mean BPI interference index, 29.1 [SD = 19.1] vs. 14.4 [SD = 14.5]). Sixty-six (44.0%) participants died during the 12-months follow-up period.

Participants reporting moderate or severe chest pain experienced poorer quality of life and none were receiving strong opioids. Given the limited prognosis, early identification of 'high risk' mesothelioma patients i.e. those who are most likely to have high symptom burden and poor prognosis, would help ensure timely input is given to implement pain management strategies. This includes Specialist Palliative Care guidance about opioid prescribing and interventional procedures. Future research should be directed towards the optimum ways to assess and improve breathlessness, without neglecting the smaller group of people who experience severe pain.