Breakthrough Cancer Pain in Patients With Abdominal Visceral Cancer Pain.

Objective: The objective of this study was to assess the characteristics of breakthrough cancer pain (BTcP) in patients with abdominal cancer pain, and the eventual factors associated with its presentation.

Methods: Patients with abdominal visceral cancer presenting BTcP were included in the analysis. Pain intensity, current analgesic therapy, number of BTcP episodes, intensity of BTcP, its predictability and triggers, onset (≤10 minutes or >10 minutes), duration, interference with daily activities, medications and doses currently used for BTcP, and time to meaningful pain relief were collected. Adverse effects imputable to a BTcP medication were recorded.

Results: Four hundred fourteen patients were included in the study. The mean background pain was 2.7 (SD 1.19) and most patients (97.6%) were receiving opioids. The mean number of BTcP episodes/day was 2.2 (SD 1.51). The mean intensity of BTcP was 7.3 (SD 1.32). BTcP onset was ≤10 minutes and >10 minutes in 271 (65.5%) and 143 patients (35.5%), respectively, and the mean duration was 52.6 minutes (SD 38.1). Interference of BTcP with daily activity was relevant for 340 patients (82%). In 122 patients (29.5%), BTcP was predictable and ingestion of food (n = 63, 51.6%) was the most frequent trigger. In comparison with unpredictable BTcP, postprandial BTcP had a lower intensity (P = 0.039), had a faster onset (P = 0.042), and was associated with the use of oxycodone/naloxone (P = 0.003), and less use of nonsteroidal anti-inflammatory drugs (P = 0.006).

Conclusion: Patients with abdominal visceral BTcP represent a subgroup with specific features of BTcP, particularly those with predictable BTcP. Ingestion of food was the prominent trigger for BTcP, having a faster onset and a lower intensity. This group of patients more frequently used oxycodone/naloxone or no anti-inflammatory drugs. These findings suggest consequential therapeutic decisions.