Breakthrough pain in patients with head & neck cancer. A secondary analysis of IOPS MS study

Aim: To characterize breakthrough pain (BTcP) in patients with Head and neck (H&N) cancer. Methods: This was a secondary analysis of multicenter study of BTcP. Background pain intensity and opioid dose were recorded. The number of BTcP episodes, their intensity, predictability, onset, duration and interference with daily activities were collected. Opioids used for BTcP, and the mean time to meaningful pain relief after taking medication, were assessed. The presence of mucositis was also assessed. Results: 205 patients with H&N cancer were examined. The mean number of BTcP episodes was 2.8/day, which was higher than in general population. The mean intensity of BTcP was 7.4. BTcP was more predictable in H&N cancer than in other tumors. The main trigger of predictable BTcP was the ingestion of food (76.5%). BTcP onset was fast in 148 patients (72.2%). The mean time to meaningful pain relief after taking a BTcP medication was 15.3 min and BTcP interference with daily activity was relevant in most patients (89.2%). Transdermal drugs and nasal fentanyl preparations were more frequently used for background pain and BTcP, respectively. A consistent number of patients with H&N cancer (38.5%) exhibited different levels of oral mucositis. Conclusion: BTcP in patients with H&N cancer is characterized by a larger number of episodes/day and the predictability, particularly with ingestion of food. The use of drugs for background analgesia and BTcP were conditioned by the possible interference with swallowing or local mucosal damage.