Discussion
The guidelines we present are the product of an international
European Palliative Care Research Collabora tive
project aimed at revising previous EAPC recommendations
for use of opioids to treat cancer pain.7 We
used a stepwise process8,9 combined with a systematic
literature review strategy. In view of the long-standing
experience with opioid analgesics, the overall poverty of
the evidence underlying many features of their use is
surprising.
The quality and the content of the most recent
evidence suggests that publication bias needs to be
taken into account. In fact, data on diff erent step III
opioids, transdermal opioids, treatments for breakthrough
pain, constipation, and neuropathic pain
derived almost entirely from RCTs sponsored by the
pharmaceutical industry. The lack of studies directly
comparing diff erent fi rst-choice step III opioids is a
clear example of such bias.
We did not assess pharmacoeconomic features. In
some cases it can be diffi cult to balance the clinical
benefi t, which is the basis for the recommendation, and
the high costs of new drugs compared with cheaper,
older, and less-eff ective drugs, such as in case of rapidonset
opioid analgesic formulations for breakthrough
pain, opioid antagonists for constipation, and others.
We are, however, deeply aware of the responsibility to
contain the cost of health care and of the potential for
opportunity cost in the use of expensive formulations of
analgesics. Socially responsible care demands that these
guidelines should be a basis for decision making that will
also take into consideration aff ordability for individual
patients and at a societal level.92 We underline that the
recom mendations are formulated under several
stipulations, as described, and should be taken as a
whole. We strongly discourage the use of any part of the
text or individual recommendations alone.
The European Palliative Care Research Collaborative
project has also highlighted the lack of consensus
regarding methods for assessment and classifi cation of
cancer pain.93 These diff erences have contributed to
suboptimum treatment of and research into cancer
pain94 because of a lack of knowledge of the eff ects of
pain characteristics on the effi cacy of opioid analgesia.
The assessment of the available limited evidence in
this fi eld can be used to identify several research
questions. The potential clinical eff ects of new pharmacological
developments (eg, tapentadol or combined
oxycodone and naloxone) need further research and
continuous updating of the guidelines is required.
Finally, the status of the EAPC opioid recommendations
can be seen as an improvement from previous standards
and is proposed as a general framework to enable
professionals, health-care authorities, and societies to
make informed decisions with the fi nal scope of
improving the quality of life for all patients affl icted by
cancer pain.