Background: Lung cancer and mesothelioma are malignant tumors with generally dismal prognosis and therefore palliative pain treatment constitutes a challenge for the clinician.
Objectives: The aim of this study was to compare the outcomes of pain treatment with opioids among mesothelioma and lung cancer patients treated for palliation and assess factors which confound to optimal treatment.
Patients and methods: A sub-cohort of 373 lung cancer and 22 mesothelioma patients was identified in multi-center European Pharmacogenetic Opioid Study (EPOS) cohort. A nested case-control (1:4) setting was designed to estimate the pain and other covariates distinguishing 22 mesothelioma- (= cases) and 88 lung cancer patients (controls), analyzed using univariate- and multivariate conditional (fixed-effects) logistic regression models.
Results: The mean total daily dose of opioids varied from 30.0 to 960.0 mg (mean 275, median 160 mg, SD 293) in mesothelioma, and from 10 to 5072 mg (mean 414, median 175, SD 788) in lung cancer patients (p = 0.420). In both groups, pain was mostly experienced as moderate and severe and it was frequently accompanied by depression, poor sleep, anxiety and fatigue. Four mesothelioma patients (18%) and seven lung cancer patients (10%) experienced complete pain relief with opioids by self-assessment. Assessments of pain severity by the patients and their physicians deviated significantly in mesothelioma (p = 0.039 McNemar test), as well as in lung cancer (p = 0.0001). In conditional logistic regression, no significant differences were found in distribution of pain covariates between lung cancer and mesothelioma patients.
Conclusion: Pain perception by the patients was associated frequently with other symptoms and complete pain control with opioids was achieved only with minority of patients both with mesothelioma and advanced lung cancer. Adequate pain control requires continuous monitoring and tailoring the dose to patient's individual needs and tolerance, recognition of accompanying symptoms such as depression and poor sleep, and their management.