A study by L. Zielger et al. (see reference below) documents the persistent undertreatment of cancer pain.
The prescriptions for analgesics issued to 6,080 UK patients during the 12 months before death were analyzed.
- Strong opioids were prescribed for 48% of patients in the last year of life.
- Median interval between first prescription of a strong opioid and death was nine weeks (interquartile range 3-23).
- Strong opioid prescribing was not influenced by cancer type, duration of illness, or gender, but was adversely influenced by older age.
- Compared with patients who died in hospice, those who died in hospital were 60% less likely to receive a strong opioid in primary care before admission.

This information displays the relatively late onset and short duration of strong opioid treatment in cancer patients.

Ziegler L et al. Opioid prescribing for patients with cancer in the last year of life: a longitudinal population cohort study. Pain 2016; 157(11): 2445-2451. Post Author Corrections: July 16, 2016.
doi: 10.1097/j.pain.0000000000000656