Hydromorphone for cancer pain

BACKGROUND

Cancer pain is an important and distressing symptom that tends to increase in frequency and intensity as the cancer advances. For people with advanced cancer, the prevalence of pain can be as high as 90%. It has been estimated that 30% to 50% of people with cancer categorise their pain as moderate to severe, with between 75% and 90% of people with cancer experiencing pain that they describe as having a major impact on their daily life. Epidemiological studies suggest that approximately 15% of people with cancer pain fail to experience acceptable pain relief with conventional management. Uncontrolled pain can lead to physical and psychological distress and can, consequently, have a drastic effect on people's quality of life.

OBJECTIVES

To determine the analgesic efficacy of hydromorphone in relieving cancer pain, as well as the incidence and severity of any adverse events.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase and clinical trials registers up to April 2016. There were no language, document type or publication status limitations applied in the search.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) that compared hydromorphone with placebo or other active pain medication for cancer pain in both adults and children. The four main outcomes selected have previously been identified as important to people with cancer; pain no worse than mild pain, and the impact of the treatment on consciousness, appetite and thirst. We did not consider physician-, nurse- or carer-reported measures of pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data. For binary outcomes, we calculated risk ratio (RR) and its 95% confidence interval (CI), on an intention-to-treat basis. For continuous data, we estimated the mean difference (MD) between groups and its 95% CI. We used a random-effects model and assessed the risk of bias for all included studies. A meta-analysis was not completed on any of the primary outcomes in this review due to the lack of data. We assessed the evidence using GRADE and created two 'Summary of findings' tables.

MAIN RESULTS

We included four studies (604 adult participants), which compared hydromorphone to oxycodone (two studies) or morphine (two studies). Overall, the included studies were at low or unclear risk of bias, rated unclear due to unknown status of blinding of outcome assessment; we rated three studies at high risk of bias for potential conflict of interest. Data for 504 participants were available for analysis. We collected data on endpoint participant-reported pain intensity measured with a visual analogue scale (VAS) (mean ± standard deviation (SD): hydromorphone 28.86 ± 17.08, n = 19; oxycodone 30.30 ± 25.33, n = 12; scale from 0 to 100 with higher score indicating worse pain), and Brief Pain Inventory (BPI) 24 hours worst pain subscale (mean ± SD: hydromorphone 3.5 ± 2.9, n = 99; morphine 4.3 ± 3.0, n = 101, scale from 0 to 10 with higher score indicating worse pain). The data demonstrated a similar effect between groups with both comparisons. The pain intensity data showed that participants in all four trials achieved no worse than mild pain. There were several adverse events: some were the expected opioid adverse effects such as nausea, constipation and vomiting; others were not typical opioid adverse effects (for example, decreased appetite, dizziness and pyrexia, as shown in Table 1 in the main review), but generally showed no difference between groups. There were three deaths in the morphine group during the trial period, considered to be due to disease progression and unrelated to the drug. Three trials had over 10% dropout, but the reason and proportion of dropout was balanced between groups. The overall quality of evidence was very low mainly due to high risk of bias, imprecision of effect estimates and publication bias. There were no data available for children or for several participant-important outcomes, including participant-reported pain relief and treatment impact on consciousness, appetite or thirst.

AUTHORS' CONCLUSIONS

This review indicated little difference between hydromorphone and other opioids in terms of analgesic efficacy. Data gathered in this review showed that hydromorphone had a similar effect on participant-reported pain intensity as reported for oxycodone and morphine. Participants generally achieved no worse than mild pain after taking hydromorphone, which is comparable with the other drugs. It produced a consistent analgesic effect through the night and could be considered for use in people with cancer pain experiencing sleep disturbance. However, the overall quality of evidence was very low mainly due to risk of bias, imprecision of effect estimates and publication bias. This review only included four studies with limited sample size and a range of study designs. Data for some important outcomes, such as impact of the treatment on consciousness, appetite or thirst, were not available. Therefore, we were unable to demonstrate superiority or inferiority of hydromorphone in comparison with other analgesics for these outcomes. We recommend that further research with larger sample sizes and more comprehensive outcome data collection is required.

[Preliminary study for the roles and mechanisms of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles in the Lewis lung cancer mice]

OBJECTIVE

To comparatively observe the effects of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles on the Lewis lung cancer mice and to explore the mechanisms of Rg3 and PEG-PLGA-Rg3 nanoparticle anti-cancer in vivo.

METHODS

Lewis lung cancer mouse model was established and 60 mice were randomly divided into 5 groups with twelve in each group: PEG-PLGA-Rg3 nanoparticles group(Rg3-N), PEG-PLGA group (PEG), Rg3 group (Rg3), normal control group(C), saline control group(NS), and received intragastric administration for 14 days. The weights of the mice were measured every 2 days and the weight curves were obtained. At the same time, the color pattern, activity and mental status were observed. The mice were sacrificed when the administration was over, and the effects of 20(R)-ginsenoside Rg3 and PEG-PLGA-Rg3 nanoparticles on tumor weight, and the tumor:weight ratios were analysed. In addition, the tumor microvessel density (MVD) was measured by immunohistochemical staining with anti-CD31 antibody to compare the effects of Rg3 and PEG-PLGA-Rg3 nanoparticles on the tumor angiogenesis in vivo. Furthermore, the levels of such angiogenesis and proliferation factors as MMP-9, HIF-1α, VEGF, Ki-67 were examined by RT-PCR, Western blot and immunohistochemistry to explore the internal molecular mechanisms of anti-tumor effects in vivo.

RESULTS

The trends of variation of the mice weights in NS group and PEG group were rising early but declining later. In contrast, the trends of the other three groups were rising early and became stable later. In comparison with NS group, the mice of Rg3 group and Rg3-N group had better general status: brighter color, more active and better spirit. Compared with NS group,the tumor weight in PEG group, Rg3 group and Rg3-N group showed no significant difference but the tumor:weight ratio and MVD in Rg3 group and Rg3-N group declined significantly (P<0.01). Besides, there was no significant difference between Rg3 group and Rg3-N group. At the same time, the level of VEGF mRNA, the protein expression of MMP-9, HIF-1α, VEGF in Rg3 group and Rg3-N group decreased compared with NS group. Furthermore, the level of each index above-mentioned in Rg3-N group was lower than that in Rg3 group. The expression of Ki-67 in PEG group, Rg3 group and Rg3-N group showed no significant difference compared with NS group.

CONCLUSION

Rg3 and PEG-PLGA-Rg3 nanoparticle may suppress the expression of VEGF, MMP-9 and HIF-1α in Lewis lung cancer mice, thereby indirectly contributing to their antitumor effects and alleviating the mice's general status. In addition, PEG-PLGA nanoparticles embedding can promote Rg3 antitumor effect in vivo.