Are strong opioids equally effective and safe in the treatment of chronic cancer pain? A multicenter randomized phase IV 'real life' trial on the variability of response to opioids.

BACKGROUND: Guidelines tend to consider morphine and morphine-like opioids comparable and interchangeable in the treatment of chronic cancer pain, but individual responses can vary. This study compared the analgesic efficacy, changes of therapy and safety profile over time of four strong opioids given for cancer pain. PATIENT AND METHODS: In this four-arm multicenter, randomized, comparative, of superiority, phase IV trial, oncological patients with moderate to severe pain requiring WHO step III opioids were randomly assigned to receive oral morphine or oxycodone or transdermal fentanyl or buprenorphine for 28 days. At each visit, pain intensity, modifications of therapy and adverse drug reactions (ADRs) were recorded. The primary efficacy end point was the proportion of nonresponders, meaning patients with worse or unchanged average pain intensity (API) between the first and last visit, measured on a 0-10 numerical rating scale. (NCT01809106). RESULTS: Forty-four centers participated in the trial and recruited 520 patients. Worst pain intensity and API decreased over 4 weeks with no significant differences between drugs. Nonresponders ranged from 11.5% (morphine) to 14.4% (buprenorphine). Appreciable changes were made in the treatment schedules over time. Each group required increases in the daily dose, from 32.7% (morphine) to 121.2% (transdermal fentanyl). Patients requiring adjuvant analgesics ranged from 68.9% (morphine) to 81.6% (oxycodone), switches varied from 22.1% (morphine) to 12% (oxycodone), discontinuation of treatment from 27% ( morphine) to 14.5% (fentanyl). ADRs were similar except for effects on the nervous system, which significantly prevailed with morphine. CONCLUSION: The main findings were the similarity in pain control, response rates and main adverse reactions among opioids. Changes in therapy schedules were notable over time. A considerable proportion of patients were nonresponders or poor responders. CLINICAL TRIAL REGISTRATION: NCT01809106 (https://clinicaltrials.gov/ct2/show/NCT01809106?term=cerp&rank=2).

Assessing the response to opioids in cancer patients: a methodological proposal and the results.

PURPOSE: The efficacy of treatment with opioids in cancer pain is variable. To evaluate this variability, we (1) applied two parameters, changes in pain intensity (PI) and opioid daily doses (DDs), to distinguish different responses to opioids. The need to switch to another opioid was recorded. We then (2) evaluated the distribution of the responses depending on these parameters, alone and taken together, in cancer patients with pain. METHODS: The cutoffs between positive and negative responses related to PI and DD were defined on the basis of the literature. For PI, responders were patients who obtained simultaneously a decrease of 30% or more and a final score ≤4 points (numerical rating scale 0 to 10). For DD changes, we applied the opioid escalation index percentage, a positive response corresponding to a dose increase ≤5%. These criteria were applied to 201 cancer patients treated with WHO step III "strong" opioids for 21 days. The results were mainly analyzed case by case. RESULTS: Of the patients, 63.7% obtained a positive analgesic response and 80.1% a dose-related positive response. Combining the parameters, the response was double positive in 55.2% of cases, double negative in 11.4%, a good analgesic response with a large dose escalation in 8.5%, and no pain relief with a stable dose in 24.9%. Switches were made 21 times, 15 because of the lack of analgesia. CONCLUSIONS: Different degrees of response to opioids were observed, PI and DD changes both contributing. Only over half the patients had a full positive response.

Pattern and quality of care of cancer pain management. Results from the Cancer Pain Outcome Research Study Group.

Most patients with advanced or metastatic cancer experience pain and despite several guidelines, undertreatment is well documented. A multicenter, open-label, prospective, non-randomised study was launched in Italy in 2006 to evaluate the epidemiology, patterns and quality of pain care of cancer patients. To assess the adequacy of analgesic care, we used a standardised measure, the pain management index (PMI), that compares the most potent analgesic prescribed for a patient with the reported level of the worst pain of that patient together with a selected list of clinical indicators. A total of 110 centres recruited 1801 valid cases. 61% of cases were received a WHO-level III opioid; 25.3% were classified as potentially undertreated, with wide variation (9.8-55.3%) according to the variables describing patients, centres and pattern of care. After adjustment with a multivariable logistic regression model, type of recruiting centre, receiving adjuvant therapy or not and type of patient recruited (new or already on follow-up) had a significant association with undertreatment. Non-compliance with the predefined set of clinical indicators was generally high, ranging from 41 to 76%. Despite intrinsic limitations of the PMI that may be considered as an indicator of the poor quality of cancer pain care, results suggest that the recourse to WHO third-level drugs still seems delayed in a substantial percentage of patients. This delay is probably related to several factors affecting practice in participating centres and suggests that the quality of cancer pain management in Italy deserves specific attention and interventions aimed at improving patients' outcomes.

A comparison between the administration of oral prolonged-release oxycodone-naloxone and transdermal fentanyl in patients with moderate-to-severe cancer pain: a propensity score analysis.

BACKGROUND: Opioids are the most important pharmacological treatment for moderate-to-severe cancer pain, but side effects limit their use. Transdermal fentanyl (TDF) and oral prolonged-release oxycodone-naloxone (OXN-PR) are effective in controlling chronic pain, with less constipation compared to other opioids. However, TDF and OXN-PR have never been directly compared. PATIENTS AND METHODS: Cancer patients with moderate-to-severe chronic pain were consecutively enrolled in two prospective 28-day trials, received either TDF or OXN-PR, and were assessed at baseline and after 7, 14, 21, and 28 days. The primary endpoint was 28-day analgesic response rate (average pain intensity decrease ≥30% from baseline). Other outcome measures included opioid daily dose changes over time; need for adjuvant analgesics; number of switches; premature discontinuation; presence and severity of constipation; and other adverse drug reactions. To compare the efficacy and the safety of TDF and OXN-PR, we used the propensity score analysis to adjust for heterogeneity between the two patient groups. RESULTS: Three hundred ten out of 336 patients originally treated (119 TDF and 191 OXN-PR) were included in the comparative analysis. The amount of responders was comparable after TDF (75.3%) and OXN-PR administration (82.9%, not significant [NS]). The final opioid daily dose expressed as morphine equivalent was 113.6 mg for TDF and 44.5 mg for OXN-PR (p<0.0001). A daily opioid dose escalation >5% was less common after OXN-PR (19.3%) than after TDS administration (37.9%, p<0.0001). Opioid switches and discontinuation were similar in both groups. Severe constipation in the two groups was comparable (32.6% after TDF vs 24.7% after OXN-PR, NS). Nausea, vomiting, and dry mouth were significantly less frequent in the OXN-PR group than in the TDF group. CONCLUSION: Despite a similar analgesic activity in moderate-to-severe cancer pain, OXN-PR is characterized by lower daily dosages, less need for drug escalation, and fewer side effects compared to TDF.

How to evaluate the effect of pain treatments in cancer patients: results from a longitudinal outcomes and endpoint Italian cohort study.

BACKGROUND: Dealing with cancer pain implies assessing the intensity and other attributes of pain and identifying appropriate outcomes and endpoints to evaluate the effect of treatments. METHODS: In the context of an observational longitudinal prospective study, 1461 painful cancer patients were evaluated at baseline and weekly over 4 weeks. Four pain intensity (PI) measures (worst, average, least and right now: WP, AP, LP, and PRN), pain relief and patients' satisfaction with pain treatments were recorded. Starting from these data, we extrapolated the full responder (FR) subjects, whose PI decreased by ≥2 points, or by ≥30%, or who obtained a final score of ≤5 points, according to criteria previously suggested by literature. The receiver operating characteristics (ROC) curve analysis was used to estimate the predictive accuracy. RESULTS: All the PI measures decreased from the initial to final visit: the reduction was 1.9 as WP, 1.3, 0.8 and 1.2 as AP, LP and PRN, respectively. The proportion of FR differed from 47.8% to 88.3% depending on PI measures and the criterion adopted. ROC analysis showed an acceptable accuracy of all endpoints and confirmed the cut-offs recommended by the literature. The best criterion corresponded to a PI absolute value of ≤4 points when measured as AP. CONCLUSIONS: All measures applied seem able to profile the evolution of pain, with some differences. This implies the need of an appropriate choice of outcomes and endpoints according to the goal and objective of the intervention under evaluation.

Evaluation of the comparative analgesic effectiveness of transdermal and oral opioids in cancer patients: a propensity score analysis.

BACKGROUND: Transdermal delivery systems containing fentanyl or buprenorphine, despite the relatively lack of comparative studies, have reached an impressive share of the market in several countries. In the context of a wider observational study, we applied the propensity score to test the comparative effectiveness of the two routes of administration (oral vs. transdermal). METHODS: We applied the propensity score in a subgroup of patients (starting the World Health Organization third step therapy during the scheduled follow-up of 28 days) using pre-planned primary (pain intensity change) and secondary endpoints, such as increase in doses, need for switching and safety profile. Univariate and multivariate analyses were carried out. RESULTS: Three-hundred sixty-six eligible cases were analysed. We found a difference among the two groups in terms of variables potentially associated with therapy choice and outcomes. After adjusting for propensity score, results were in favour of transdermal delivery systems for the primary endpoint (odds ratio 1.68; p = 0.04). A similar trend was also present for the other secondary endpoints. Only in the case of nausea and vomiting, patients receiving transdermal delivery systems reported a higher frequency of events. CONCLUSION: The application of the propensity score has helped understand better the actual effectiveness of transdermal delivery systems that are at least equivalent to the oral opioids, and even more effective for pain intensity reduction.