Prescription patterns of analgesics in cancer patients with bone metastases in Japan: a retrospective database study.

BACKGROUND: Real-world data on optimal cancer pain management remain scarce. We describe prescription patterns of analgesics in Japanese cancer patients with bone metastases.

METHODS: National hospital-based claims data were analyzed. Adults with first diagnosis of cancer during 2015-2019 and first diagnosis of bone metastasis after the initial cancer diagnosis were included. Skeletal-related events (SREs) were identified with disease and receipt codes.

RESULTS: Among the 40,507 eligible patients (age [mean ± SD], 69.7 ± 11.7 years), lung (25.3%), prostate (15.6%), breast (10.9%), and colorectal (10.7%) cancers were common primary tumors. Time (mean ± SD) between primary cancer diagnosis and bone metastases was 306.9 ± 490.4 days; median survival time from bone metastases was 483.0 days. Most patients used acetaminophen (62.7%, 117.5 days/year) and nonsteroidal anti-inflammatory drugs (NSAIDs; 75.3%, 170.0 days/year). Commonly used opioids included oxycodone (39.4%; 479.3 days/year), fentanyl (32.5%; 52.6 days/year), morphine (22.1%; 130.9 days/year), and tramadol (15.3%; 143.0 days/year). Internal medicine, surgery, respiratory, urology, and orthopedics treated 19.4%, 18.5%, 17.6%, 17.3%, and 13.0% of patients, respectively. Prescription patterns varied inter-department. Overall, 44.9% of patients developed SRE (bone pain requiring radiation [39.6%] or orthopedic surgery [2.9%]; hypercalcemia, 4.9%; pathological fracture, 3.3%; spinal cord compression, 0.4%). Analgesics use by patients with SREs was 1.8- to 2.2-fold in the postsymptomatic vs the presymptomatic period. SRE patients had numerically lower survival probabilities than non-SRE patients. Opioid use increased considerably in the month before death.

CONCLUSION: In Japanese cancer patients with bone metastases, acetaminophen, NSAIDs, and weak or strong opioids were commonly used; their use increased after SREs developed. Opioid use increased closer to death.