Breakthrough cancer pain in 2020.

PURPOSE OF REVIEW: An overview on breakthrough cancer pain (BTCP), including inherent limitations of the terminology, assessment, clinical presentation, and treatment options. RECENT FINDINGS: The estimated prevalence of BTCP is dependent on the defined cutoffs for controlled background pain and the magnitude of the pain flare. In addition, pain flares outside the definition of BTCP are prevalent. In the 11th Revision of the International Classification of Diseases, the temporal characteristics of cancer pain are described as continuous background pain and intermittent episodic pain. BTCP should be assessed by validated methods, and the patient perspective should be included. The pain may be related to neoplastic destruction of bone, viscera, or nerve tissue and is characterized by rapid onset, high intensity, and short duration. Treatment directed towards painful metastases must be considered. Due to pharmacological properties mirroring the pain characteristics, transmucosal fentanyl formulations are important for the treatment of BTCP. Oral immediate release opioids can be used for slow-onset or predictable BTCP. For more difficult pain conditions, parenteral, or even intrathecal pain medication, may be indicated. SUMMARY: All clinically relevant episodic pains must be adequately treated in accordance with the patient's preferences. Transmucosal fentanyl formulations are effective for BTCP.