One in three of the population will develop cancer at some time in their life, and one in four will die from their disease. There were more than 250 000 new cases of cancer last year in England and Wales, and more than 27000 in Scotland.
Two-thirds of cancer patients will experience severe pain related to their cancer, but this can be adequately controlled in 88% of cases by applying the basic principles of pain management.1
"The greatest cause of suffering is the failure to apply current knowledge"
Director, WHO Cancer Pain Relief Programme
Unfortunately, control of cancer pain in general practice is variable, for a variety of reasons.2 Lack of sufficient GP and district nurse time to enable the frequent assessment and reassessment that is required to bring acute cancer pain under control quickly and effectively is one factor; another is non-availability of drugs and equipment out of hours. However, failure to apply the basic principles of pain management is also undoubtedly a significant influence.
Although there are many guidelines on pain control in existence, it is timely for the Scottish Intercollegiate Guidelines Network (SIGN) to publish a guideline that is clearly evidence based – Control of Pain in Patients with Cancer (SIGN Guideline No. 44).3
Most GPs consider palliative care to be a core element of general practice and, given the time, are keen to ensure optimal care for such patients.
We also know that, at present, around 25% of cancer patients die at home,4-6 but many more die in institutions, and that, given the choice, this latter group would choose to be cared for and to die at home. If the resources can be found to enable more people to stay at home if that is their wish, then GPs will be more involved in palliative care.
Development of the guideline
A broad range of disciplines was represented on the multidisciplinary group that was formed under the chairmanship of Professor John Welsh, Olav Kerr Professor of Palliative Medicine at Glasgow University (a post funded by Macmillan Cancer Relief). They included nursing, psychology, pharmacy, oncology, management, occupational therapy and anaesthetics, as well as palliative medicine and general practice.
The voluntary sector was represented by the Director of the Scottish Partnership Agency for Cancer and Palliative Care, and there was a representative from a regional health council.
The difficulties in identifying patient representatives of this clinical situation who could contribute to a process that was anticipated to take around 3 years were considered to be too great for this to be feasible. However, the inclusion of two lay people on the group went some way to addressing this shortfall. SIGN is committed to ensuring that the voice of service users is heard.
The guideline development group was subdivided into different subgroups that were each allocated a particular section of the outline document. Each subgroup was given the task of reviewing the literature and grading the evidence.
Here we were indebted to the SIGN information office for conducting the searches. The whole process was facilitated by staff of the Scottish Cancer Therapy Network.
The subgroups dealt with the following areas:
- Assessment of cancer pain
- Non-physical pain
- Communication issues
I was allocated to the assessment group, and although there were comparatively few references to review, I found the process quite demanding of time, energy and intellect. I now have much more respect for those who conduct meta-analyses and literature reviews.
The guideline quotes 216 references. This evidence was graded accordingly and recommendations were made according to SIGN methodology.
The recommendations are graded as follows:
- Grade A – Based on evidence levels Ia, Ib
- Grade B – Based on evidence levels IIa, IIb, III
- Grade C – Based on evidence level IV.
In the Quick Reference Guide (see Figure 1a-d, below) there are:
- 10 Grade A recommendations
- 22 Grade B recommendations
- 18 Grade C recommendations
- 6 'Good Practice' points
I commend the Quick Reference Guide to all GPs. It is a useful summary of our deliberations, and if followed should increase the percentage of patients with cancer pain whose pain is adequately controlled.
WHO analgesic ladder
There is good evidence that involving patients in their care by giving them adequate information and instruction does improve pain control.
The basic principles of pain control in the guidelines are based on the WHO Cancer Pain Relief Programme. These emphasise the use of the WHO analgesic ladder, which descibes a treatment strategy for the three steps of the ladder:
- mild pain
- mild to moderate pain
- moderate to severe pain.
The analgesic ladder is reproduced in full in the Quick Reference Guide.
There is also encouragement to use opioids at an earlier stage in patients with moderate to severe cancer pain rather than trying a number of different non-opioid analgesics.
The importance of accurate assessment is highlighted, and the point made that the patient should be the prime assessor of the pain.
We know there are many factors that influence pain, in addition to the physical and functional. Such factors include psychosocial and spiritual dimensions.
There is some evidence that the use of a formal assessment tool does improve management. Such tools are not used much in general practice at present, but they do form part of audit tools that will be used more widely in future as quality assurance processes are developed for clinical governance purposes.
Assessment should also include determination of the psychological and social state, looking particularly for anxiety and depression which tend to be under-recognised.
All GPs should be very familiar with the use of opioids. Although there is not a lot of high grade evidence to support the recommendations, few would argue with initially titrating with normal release morphine to establish the dose required over a 24-hour period, before conversion to controlled release morphine.
One factor that has been identified as contributing to poor control has been failure of the dose of opioid for breakthrough pain to keep up with the increase in the 24-hour total dose. It should be one sixth of the total 24-hour dose.
The prophylactic use of laxatives is important in preventing constipation – a very common complication of opioid use. Other side-effects can and should be anticipated.
There are guidelines on toxicity, tolerance and dependence, and the use of the subcutaneous route when moving to parenteral administration is highlighted.
Other avenues for pain relief
There is good evidence supporting the use of adjuvant analgesics such as tricyclic antidepressants in patients with neuropathic pain.
Although dexamethasone is widely used in a number of clinical situations to reduce pressure and thereby reduce pain, the evidence is less robust.
There is also good evidence for the use of certain systemic anti-cancer drugs. Again, although the evidence is surprisingly low grade, it is known that radiotherapy can be helpful for painful bone metastases.
Bisphosphonates have been shown to be very effective in reducing pain in patients with multiple myeloma and in breast cancer patients with metastatic bone disease.
There has been remarkably little research into interventional techniques, but there is good evidence that coeliac plexus block is effective, especially in secondary pancreatic cancer.
Because of the prevalence of cancer pain, it is vital that all health professionals caring for such patients should have appropriate and ongoing education in pain management.
The key to improving pain relief in general practice is ensuring that GPs and district nurses have confidence in their knowledge of opioids, and introduce them earlier rather than later. They must be conversant with assessment, tritation and conversion to slow-release preparations. They must be conscious of ensuring an appropriate dose for breakthrough pain and must anticipate side-effects.
The oral route is always preferable, and the subcutaneous route should be used when the oral route is no longer available.
The importance of audit should also be emphasised, with the use of the minimum data set of the guideline as a good starting point. I would encourage all GPs to adopt this guideline as a priority.
- Copies of SIGN guideline no. 44 Control of Pain in Patients with Cancer may be ordered from the SIGN Secretariat, Royal College of Physicians, 9 Queen Street, Edinburgh EH2 1JQ, or can be downloaded free of charge from the SIGN website at: www.sign.ac.uk
- Zech DF, Grond S, Lynch J, Hertel D, Lehmann KA. Validation of World Health Organization guidelines for cancer pain relief: a 10-year prospective study. Pain 1995; 61: 277-84.
- Addington-Hall JM, McCarthy M. Regional study of care for the dying: methods and sample characteristics. Palliat Med 1995; 9: 27-35.
- Scottish Intercollegiate Guidelines Network and Scottish Cancer Therapy Network. Control of Pain in Patients with Cancer. Edinburgh: SIGN, June 2000.
- Millar DG, Carroll D, Grimshaw J, Watt B. Palliative care at home: an audit of cancer deaths in Grampian region. Br J Gen Pract 1998; 48: 1299-302.
- Higginson IJ, Astin A, Dolan S. Where do cancer patients die? Ten-year trends in the place of death of cancer patients in England. Palliat Med 1998; 12: 353-63.
- Davison D, Johnston G, Reilly P, Stevenson M. Where do patients with cancer die in Belfast? Irish J Med Sci 2001 (in press).