Breakthrough pain in patients with abdominal cancer pain.

Abstract

Abstract OBJECTIVE: Characterization of breakthrough cancer pain (BTcP) in patients with abdominal cancer is lacking. The aim of this study was to assess the characteristics of BTcP in patients with abdominal cancer pain. PATIENTS AND METHODS: In an observational cohort study, from a consecutive sample of patients admitted to a pain relief and supportive care unit for a period of 13 months, patients with abdominal disease due to cancer, including primary cancer or metastases, were assessed for the presence of chronic abdominal pain; its mechanism, intensity of background pain, and pain flares, which were distinguishable from the baseline pain, were recorded. Patients presenting with pain flares were assessed regarding the causes and the possible factors associated with it. Patients were reassessed when background pain control was considered optimal. RESULTS: From a sample of 522 patients admitted to an acute pain relief and palliative care unit in a period of 13 months, 100 patients with abdominal disease were available. The mean age was 65.3 years (SD±11.4); of the 100 patients, 45 (45%) were males. The mean Karnofsky status was 47.7 (SD±11.1). At admission (T0), 67 patients (67%) had background pain with mean pain intensity of 4.9 (SD±1.6). Sixty-one patients of those with background pain (91%) had superimposed and well-distinguished pain flares. After analgesic optimization (T1), the mean background pain intensity was 1.7 (SD±1.2), and 55.2% of patients had BTcP episodes. The difference with T0 was significant (P<0.0005). CONCLUSIONS: This preliminary study provides new insights on the characteristics of BTcP in a subclass of patients with abdominal disease. It has been estimated that about 55% of patients with well-controlled background pain will develop BTcP episodes. This percentage was higher (about 90%) in patients who presented with uncontrolled background pain, underlying the need to better characterize patients with BTcP, only after a careful optimization of basal pain, as considered by the definition of BTcP.