High opioid exposure is a prognostic factor for shorter overall survival, according to a study presented here at the 2015 American Society of Clinical Oncology (ASCO) Palliative Care in Oncology Symposium.
The study involved patients with stage IV non-hematologic malignancies. For these and other patients with advanced cancer, pain is a challenging problem.
“Opioids are commonly used for mitigation of cancer-related pain but may be associated with tumour progression and shorter survival,” wrote Dylan Zylla, MD, Park Nicollet Health Partners, Minneapolis, Minnesota, and colleagues in their presentation. “We recently reported that high opioid use during the first 90 days after diagnosis is associated with shorter survival in patients with advanced lung cancer.”
The current study analysed data from 1,386 patients with newly diagnosed stage IV non-hematologic malignancies from 2005-2013. Data concerning pain and opioid utilisation within 90 days of treatment were gathered from electronic medical records and a tumour registry. Opioid utilisation was stratified into low opioid exposure (no opioid prescriptions or 1 prescription for a short-acting opioid; n = 499) and high opioid exposure (any long-acting opioid prescription or ≥2 short-acting opioid prescriptions; n = 887).
At the time of analysis, 76.0% and 82.8%, respectively, of the patients had died.
Moderate to severe pain levels were higher in the high opioid exposure group compared with the low opioid exposure group (29.3% vs 14.0%; P < .0001).
High opioid exposure resulted in shorter median overall survival (14.4 vs 21.6 months; P < .0001). The greater use of opioids was independently associated with worse overall survival (hazard ratio [HR] = 1.39; P < .0001).
Other independent factors of worse overall survival were worse tumour prognosis (HR = 3.35; P < .0001) and age at diagnosis (HR = 1.03; P < .0001).
“The impact of opioid use remained significant even when adjusting for age, tumour type, and gender,” the authors wrote. “There is likely a complex interplay between pain, opioid use, and cancer progression, making it difficult to dissociate pain from opioid use.”
The researcher suggested that tracking opioid use in the first 90 days of cancer diagnosis could help clinicians in clarifying the outcome of their patients with advanced non-hematologic malignancies.
“Further prospective investigation on the role of opioid receptors and opioid utilisation is urgently needed,” the authors concluded.
[Presentation title: Impact of Opioid Use on Survival in Patients With Newly Diagnosed Stage IV Non-Hematologic Malignancies. Abstract 188]