Many terminal cancer patients are not getting adequate pain relief early enough, according to a University of Leeds study.
The researchers found that, on average, terminal cancer patients were given their first dose of a strong opioid such as morphine just nine weeks before their death.
Yet many people with terminal cancer suffer with pain a long time before that, the researchers said.
"We have identified for the first time the relatively late onset and short duration of strong opioid treatment in cancer patients prior to death," said lead study author Dr Lucy Ziegler, a senior research fellow in palliative care at the University of Leeds.
"This pattern of prescribing does not match population data which points to earlier onset of pain.
"Nine weeks before death is considered late in the course of the cancer trajectory.
"Although the prevalence of pain is higher in patients with advanced cancer and towards the end of life, for many patients pain is experienced at many stages throughout the illness.
"In fact, pain is the most common presenting symptom at diagnosis.
"Our research highlights the need to prioritise earlier access to effective pain management for patients with advanced cancer."
The research team used UK Cancer Registry data to study a sample of 6,080 patients who died of the disease between 2005 and 2012.
They analysed the anonymised corresponding primary care medical records of the patients to find out their prescription history.
They found that 48 per cent of the patients were issued a prescription in general practice (primary care) for a strong opioid medication, such as morphine, during the last year of their life.
The median interval between first prescription and death was nine weeks.
"We examined whether late diagnosis could account for this, but median survival for our sample from diagnosis was 60 weeks, suggesting that most opioid prescribing in fact occurred late in the trajectory between diagnosis and death, regardless of cancer duration," said Mike Bennett, a professor of palliative medicine at the University of Leeds, who co-authored the research.
"In addition, over 90 per cent of all patients in the cohort had received some form of cancer treatment, therefore it was not the absence of a cancer diagnosis or poor engagement with cancer services that hindered timely access to an opioid."
The study found that over-60s were more likely to be prescribed drugs late than younger people, while those who died in a hospice (rather than in hospital, at home or in a care home) were more likely to have been prescribed drugs earlier.
The research team, whose study is published in the medical journal Pain, said efforts to improve treatment of cancer pain may be being hindered by concern over the ongoing 'opioid epidemic'.
They cited NHS data which showed that overall opioid prescribing increased by 466 per cent between 2000 and 2010, but only increased by 16 per cent for patients with cancer.
Although the University of Leeds researchers did not examine pain severity, previous studies have found that up to 86 per cent of patients with advanced cancer will experience pain.
"Within the advanced cancer population there is a need to develop mechanisms to improve pain assessment and initiate a more proactive approach to prescribing, particularly for older patients," said Dr Ziegler.
"Effective pain control is fundamental to good quality of life. For patients who are approaching the end of their lives it is crucially important we strive to get this right and that we help them achieve the best quality of life possible.
"One mechanism to achieve this may be through earlier integration of specialist palliative care and we are exploring in a related study funded by Yorkshire Cancer Research whether contact with palliative care services improves access to opioids."
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