Background:

Opioids are widely used for the treatment of cancer pain and non-malignant pain. There is a lot of information about opioid misuse (OM) in patients with non-malignant pain, however in cancer patients there is less evidence.

Objectives:

To identify, appraise and synthesize existing evidence about epidemiology, risk factors, clinical tools and evolution of OM in patients with cancer pain.

Methods:

Integrative systematic review with data extraction and narrative synthesis. PubMed, Web of Science y PsychINFO databases were searched for articles published through 31 December 2017. Study inclusion criteria were as follows: 1) published in English, Spanish or French language; and 2) containing data on the preva-lence or incidence of OM in patients with cancer pain; or/and 3) providing information about OM risk factors, mortality, duration and remission.

Results:

The search yielded 3520 articles, of which 40 met the inclusion criteria. Four themes were identified: 1) epidemiology, 2) risk factors, 3) patient's and professional's opinion, and 4) specific policies. The obtained results were very heterogeneous; the pre-valence of OM varied from 0 up to 26 % and the preva-lence of opioid-associated aberrant behaviours from 12 to 85 %. Different risk factors for OM were identified, highlighting young age and history of psychiatric disorders or substance abuse, and different tools for risk assessment or diagnosis of OM were described. Regarding professional's opinion, it seems to be more awareness about OM but nevertheless policies regarding this problem are scarce.

Conclusions:

Even though there is a greater awareness among professionals about OM in cancer patients, the current information is very heterogeneous and does not allow clear conclusions. For this reason, it will be necessary to carry out new studies trying to standardize criteria and establish better protocols and policies for detection and management of OM.

        · abstract in Spanish     · text in English | Spanish     · English ( pdf ) | Spanish ( pdf )