Opioid initiation timing and palliative care referrals in advanced cancer: retrospective study.

Objectives: Early opioid initiation is recommended for advanced cancer pain, however the timing of opioid commencement in relation to diagnosis has not been described, and the role of palliative care prescribers is unclear. This study aims to determine the timing of opioid initiation by prescriber and cancer type in relation to key timepoints in the cancer illness course (diagnosis, palliative care referral and death).

Methods: This retrospective cohort study included patients at a quaternary cancer centre with incurable advanced cancer of five different subtype groups. Demographics, clinical characteristics, health service use and details of first slow and immediate release opioid prescription are reported.

Results: Among 200 patients, median time to first immediate release opioid prescription was 23 days (IQR 1-82) and to slow release opioid prescription was 47 days (IQR 14-155). Most patients (95%, (n=190) were referred to palliative care (median time to referral 54 days (IQR 18-190)). Non-palliative care prescribers initiated slow release opioids for half the cohort (49%, n=97) prior to referral. Patients with pancreatic cancer had the shortest time to slow/immediate release opioid prescription (median 10 days (IQR 0-39) and 26 days (IQR 1-43) respectively) and shortest survival (median 136 days (IQR 82-214)).

Conclusions: Median time to opioid commencement was approximately 3 weeks after diagnosis. Despite early palliative care involvement, opioid initiation by non-palliative care clinicians was common and remains important. Timely palliative care referral for those with pancreatic cancer may include consideration of earlier complex pain presentations and shorter prognosis.