Opioid analgesics for nociceptive cancer pain: A comprehensive review.

Pain is one of the most burdensome symptoms in people with cancer, and opioid analgesics are considered the mainstay of cancer pain management. For this review, the authors evaluated the efficacy and toxicities of opioid analgesics compared with placebo, other opioids, nonopioid analgesics, and nonpharmacologic treatments for background cancer pain (continuous and relatively constant pain present at rest), and breakthrough cancer pain (transient exacerbation of pain despite stable and adequately controlled background pain). They found a paucity of placebo-controlled trials for background cancer pain, although tapentadol or codeine may be more efficacious than placebo (moderate-certainty to low-certainty evidence). Nonsteroidal anti-inflammatory drugs including aspirin, piroxicam, diclofenac, ketorolac, and the antidepressant medicine imipramine, may be at least as efficacious as opioids for moderate-to-severe background cancer pain. For breakthrough cancer pain, oral transmucosal, buccal, sublingual, or intranasal fentanyl preparations were identified as more efficacious than placebo but were more commonly associated with toxicities, including constipation and nausea. Despite being recommended worldwide for the treatment of cancer pain, morphine was generally not superior to other opioids, nor did it have a more favorable toxicity profile. The interpretation of study results, however, was complicated by the heterogeneity in the study populations evaluated. Given the limited quality and quantity of research, there is a need to reappraise the clinical utility of opioids in people with cancer pain, particularly those who are not at the end of life, and to further explore the effects of opioids on immune system function and quality of life in these individuals.

Optimal pain management for patients with cancer in the modern era.

Pain is a common symptom among patients with cancer. Adequate pain assessment and management are critical to improve the quality of life and health outcomes in this population. In this review, the authors provide a framework for safely and effectively managing cancer-related pain by summarizing the evidence for the importance of controlling pain, the barriers to adequate pain management, strategies to assess and manage cancer-related pain, how to manage pain in patients at risk of substance use disorder, and considerations when managing pain in a survivorship population. CA Cancer J Clin 2018;68:182-196. © 2018 American Cancer Society.

Palliative radiotherapy versus best supportive care in patients with painful hepatic cancer (CCTG HE1): a multicentre, open-label, randomised, controlled, phase 3 study.

BACKGROUND: Palliative treatment options for painful hepatic cancer can be restricted due to patients eventually becoming refractory to standard treatment. The aim of this study was to determine whether radiotherapy improves hepatic pain from cancer. METHODS: In this open-label, randomised, controlled, phase 3 trial (CCTG HE1) done in nine cancer centres across Canada, we included patients aged 18 years or older with hepatocellular carcinoma or liver metastases, who were refractory to standard treatment, with an Eastern Cooperative Oncology Group performance status of 0-3, with life expectancy of more than 3 months, and pain or discomfort at its worst in the past 24 hours on the Brief Pain Inventory (BPI) of at least 4 out of 10, which was stable for up to 7 days before randomisation. Patients were randomly assigned (1:1), via a minimisation method after stratification by centre and type of cancer (hepatocellular carcinoma vs liver metastases), to single-fraction radiotherapy (8 Gy) to the liver with 8 mg ondansetron (or equivalent) orally and 4 mg dexamethasone orally given 1-2 h before radiotherapy plus best supportive care (including non-opioid or opioid analgesia, or dexamethasone, or a combination of these) or best supportive care alone. The primary endpoint was improvement in patient-reported liver cancer pain or discomfort of at least 2 points on worst pain intensity on the BPI at 1 month after randomisation. All patients with both baseline and 1-month assessments were included in the primary endpoint analysis. Safety was assessed in all patients randomly assigned to treatment. This trial is registered with ClinicalTrials.gov, NCT02511522, and is complete. FINDINGS: Between July 25, 2015, and June 2, 2022, 66 patients were screened and randomly assigned to radiotherapy plus best supportive care (n=33) or best supportive care (n=33). Median age was 65 years (IQR 57-72), 37 (56%) of 66 patients were male, 29 (44%) were female, 43 (65%) had liver metastases, and 23 (35%) had hepatocellular carcinoma (data on race and ethnicity were not collected). As of data cutoff (Sept 8, 2022), median follow-up was 3·2 months (95% CI 3·0-3·4). 24 (73%) of 33 in the radiotherapy plus best supportive care group and 18 (55%) of 33 in the best supportive care only group completed baseline and 1-month assessments. An improvement in hepatic pain of at least 2 points in worst pain intensity on the BPI at 1 month was seen in 16 (67%) of 24 patients in the radiotherapy plus best supportive care group versus four (22%) of 18 patients in the best supportive care group (p=0·0042). The most common grade 3-4 adverse events within 1 month after randomisation were abdominal pain (three [9%] of 33 in the radiotherapy group vs one [3%] of 33 in best supportive care group) and ascites (two [6%] vs one [3%]). No serious adverse events or treatment-related deaths were observed. INTERPRETATION: Single-fraction radiotherapy plus best supportive care improved pain compared with best supportive care alone in patients with liver cancer, and could be considered a standard palliative treatment. FUNDING: Canadian Cancer Society.

Celiac plexus radiosurgery for pain management in advanced cancer: a multicentre, single-arm, phase 2 trial.

BACKGROUND: Refractory upper abdominal pain or lower back pain (retroperitoneal pain syndrome) related to celiac plexus involvement characterises pancreatic and other upper gastrointestinal malignancies and is an unmet need. We hypothesised that ablative radiation delivered to the celiac plexus would decrease pain. METHODS: This multicentre, single-arm, phase 2 study was done at eight hospitals in five countries (Israel, Poland, Canada, the USA, and Portugal). Eligible patients aged 18 years or older with an average pain level of 5-10 on the Brief Pain Inventory short form (BPI-SF), an Eastern Cooperative Oncology Group performance status score of 0-2, and either pancreatic cancer or other tumours involving the celiac axis, received a single fraction of 25 Gy of external-beam photons to the celiac plexus. The primary endpoint was complete or partial pain response based on a reduction of the BPI-SF average pain score of 2 points or more from baseline to 3 weeks after treatment. All evaluable patients with stable pain scores were included in response assessment. The trial is registered with ClinicalTrials.gov, NCT03323489, and is complete. FINDINGS: Between Jan 3, 2018, and Dec 28, 2021, 125 patients were treated, 90 of whom were evaluable. Patients were followed up until death. Median age was 65·5 years (IQR 58·3-71·8), 50 (56%) were female and 40 (44%) were male, 83 (92%) had pancreatic cancer, and 77 (86%) had metastatic disease. Median baseline BPI-SF average pain score was 6 (IQR 5-7). Of the 90 evaluable patients at 3 weeks, 48 (53%; 95% CI 42-64) had at least a partial pain response. The most common grade 3-4 adverse events, irrespective of attribution, were abdominal pain (35 [28%] of 125) and fatigue (23 [18%]). 11 serious adverse events of grade 3 or worse were recorded. Two grade 3 serious adverse events were probably attributed to treatment by the local investigators (abdominal pain [n=1] and nausea [n=1]), and nine were possibly attributed to treatment (seven were grade 3: blood bilirubin increased [n=1], duodenal haemorrhage [n=2], abdominal pain [n=2], and progressive disease [n=2]; and two were grade 5: gastrointestinal bleed from suspected varices 24 days after treatment [n=1] and progressive disease [advanced pancreatic cancer] 89 days after treatment [n=1]). INTERPRETATION: Celiac plexus radiosurgery could potentially be a non-invasive palliative option for patients with retroperitoneal pain syndrome. Further investigation by means of a randomised comparison with conventional celiac block or neurolysis is warranted. FUNDING: Gateway for Cancer Research and the Israel Cancer Association.

Study of the relationship between psychoactive substance use and pain in cancer patients and cancer survivors: A French nationwide cross-sectional study.

Pain is a prevalent symptom among cancer patients and survivors. Psychoactive substance use (PSU) is associated with both the presence and severity of pain. However, little is known about this association in the context of cancer. The primary objective was to compare the prevalence of PSU and its relationship with pain during and after cancer. PSU was defined as the use of nonmedication substances (alcohol, tobacco, e-cigarettes, cannabidiol, and cannabis), with frequency categorized as at least yearly, monthly, weekly, or daily. Secondary objectives aimed to explore the relationships between PSU and pain characteristics, health-related quality of life, anxiety, depression, deprivation, and individual characteristics. Among the 1041 individuals included, pain prevalence was 44.7% (95% confidence interval [CI] 41.6%-47.8%). The overall prevalence of PSU at least monthly was 67.0% (95% CI 64.0%-69.8%). The proportions of chronic and neuropathic pains were higher for at least monthly use of cannabidiol compared to nonuse (70.0% vs. 39.3% and 55.7% vs. 28.1%, p < .001). In multivariate analysis, the monthly uses of tobacco and cannabidiol were higher in painful individuals than in nonpainful ones (odds ratio: 2.85 [95% CI 1.22-6.64] and 3.76 [95% CI 1.13-12.44], p < .05). From the point of view of the patient care, the study underscores the need for physicians to prioritize smoking cessation and pay attention to the use of cannabidiol during and after cancer.

Electroacupuncture attenuates nociceptive behaviors in a mouse model of cancer pain.

Pain is a major symptom in cancer patients, and cancer-induced bone pain (CIBP) is the most common type of moderate and severe cancer-related pain. The current available analgesic treatments for CIBP have adverse effects as well as limited therapeutic effects. Acupuncture is proved effective in pain management as a safe alternative therapy. We evaluated the analgesic effect of acupuncture in treatment of cancer pain and try to explore the underlying analgesic mechanisms. Nude mice were inoculated with cancer cells into the left distal femur to establish cancer pain model. Electroacupuncture (EA) treatment was applied for the xenograft animals. Pain behaviors of mice were evaluated, followed by the detections of neuropeptide-related and inflammation-related indicators in peripheral and central levels. EA treatment alleviated cancer-induced pain behaviors covering mechanical allodynia, thermal hyperalgesia and spontaneous pain, and also down-regulated immunofluorescence expressions of neuropeptide CGRP and p75 in the skin of affected plantar area in xenograft mice, and inhibited expressions of overexpressed neuropeptide-related and inflammation-related protein in the lumbar spinal cord of xenograft mice. Overall, our findings suggest that EA treatment ameliorated cancer-induced pain behaviors in the mouse xenograft model of cancer pain, possibly through inhibiting the expressions of neuropeptide-related and inflammation-related protein in central level following tumor cell xenografts.

Esketamine inhibits the c-Jun N-terminal kinase pathway in the spinal dorsal horn to relieve bone cancer pain in rats.

Cancer-induced bone pain (CIBP) is one of the most common and feared symptoms in patients with advanced tumors. The X-C motif chemokine ligand 12 (CXCL12) and the CXCR4 receptor have been associated with glial cell activation in bone cancer pain. Moreover, mitogen-activated protein kinases (MAPKs), as downstream CXCL12/CXCR4 signals, and c-Jun, as activator protein AP-1 components, contribute to the development of various types of pain. However, the specific CIBP mechanisms remain unknown. Esketamine is a non-selective N-methyl-d-aspartic acid receptor (NMDA) inhibitor commonly used as an analgesic in the clinic, but its analgesic mechanism in bone cancer pain remains unclear. We used a tumor cell implantation (TCI) model and explored that CXCL12/CXCR4, p-MAPKs, and p-c-Jun were stably up-regulated in the spinal cord. Immunofluorescence images showed activated microglia in the spinal cord on day 14 after TCI and co-expression of CXCL12/CXCR4, p-MAPKs (p-JNK, p-ERK, p-p38 MAPK), and p-c-Jun in microglia. Intrathecal injection of the CXCR4 inhibitor AMD3100 reduced JNK and c-Jun phosphorylations, and intrathecal injection of the JNK inhibitor SP600125 and esketamine also alleviated TCI-induced pain and reduced the expression of p-JNK and p-c-Jun in microglia. Overall, our data suggest that the CXCL12/CXCR4-JNK-c-Jun signaling pathway of microglia in the spinal cord mediates neuronal sensitization and pain hypersensitivity in cancer-induced bone pain and that esketamine exerts its analgesic effect by inhibiting the JNK-c-Jun pathway.

Virtual reality for pain management in hospitalized patients with cancer: A randomized controlled trial.

BACKGROUND: Hospitalized patients with cancer often experience acute and/or chronic pain. Although virtual reality (VR) has been extensively studied across a wide range of clinical settings, no studies have yet evaluated potential impact on pain management in this patient population. METHODS: Prospective randomized controlled trial at an urban academic hospital comparing VR against an active control to mitigate moderate-severe cancer disease and treatment-related pain. RESULTS: A total of 128 adult hospitalized patients with cancer (any tumor type) were randomized to 10 minutes of immersive VR distraction therapy or 10 minutes of two-dimensional guided imagery distraction therapy delivered by handheld tablet. Participants in the two arms were similar in age, sex, race, presence of metastatic disease, concurrent pain specialist consultation, and baseline opioid use. Although both groups experienced improved self-reported pain scores (primary outcome), those randomized to VR experienced significantly greater reduction in pain immediately after intervention compared with active control (p = .03). This difference was sustained for 24 hours as well (p = .004). Within-group analysis showed significant improvement in VR arm of pain bothersomeness (p = .05) and general distress (p = .03) as well. CONCLUSION: Among hospitalized adult patients with moderate-severe pain related to cancer and cancer therapies, VR provided more nonpharmacologic pain relief than active control and this benefit sustained long after conclusion of the intervention. PLAIN LANGUAGE SUMMARY: Virtual reality (VR), a developing technology that immerses the user in new environments, has been shown to improve pain in different patient populations. To test the role of VR in improving pain in hospitalized patients with cancer who report moderate-severe pain, we compared the impact of a 10-minute immersive VR intervention to that of a 10-minute two-dimensional guided imagery experience to improve self-reported pain scores. We found that, although both interventions improved pain, VR did so significantly more. Moreover, participants assigned to VR had sustained improvement in pain 24 hours later.

Toward reducing racialized pain care disparities: Approaching cannabis research and access through the lens of equity and inclusion.

There is growing interest in cannabis use for cancer pain. This commentary aims to discuss the evidence surrounding cannabis use for cancer pain in the context of the long-racialized landscape of cannabis policies and the disparity in pain control among cancer patients holding minoritized racial identities. Much evidence surrounding both the benefits and harms of cannabis use in cancer patients, and all patients in general, is lacking. Although drawing on the research in cancer that is available, it is also important to illustrate the broader context about how cannabis' deep roots in medical, political, and social history impact patient use and health care policies. There are lessons we can learn from the racialized disparities in opioid risk mitigation strategies, so they are not replicated in the settings of cannabis for cancer symptom management. Additionally, the authors intentionally use the term "cannabis" here rather than "marijuana.: In the early 1900s, the lay press and government popularized the use of the word "marijuana" instead of the more common "cannabis" to tie the drug to anti-Mexican prejudice.

Dose-intensified stereotactic body radiotherapy for painful vertebral metastases: A randomized phase 3 trial.

BACKGROUND: The purpose of this randomised study was to determine whether dose-intensified stereotactic body radiotherapy (SBRT) for painful vertebral metastases results in increased rates of pain improvement compared with conventional external beam radiotherapy (cEBRT) (control) 6 months after treatment. METHODS: This randomized, controlled phase 3 trial was conducted between November 2016 and January 2023, when it was stopped early. Patients were eligible if they were aged 18 years or older; had one or two painful, stable, or potentially unstable vertebral metastases; and had a life expectancy of 1 year or longer according to the investigator's estimates. Patients received 48.5 grays (Gy) in 10 fractions (with epidural involvement) or 40 Gy in five fractions (without epidural involvement) in the SBRT group and 30 Gy in 10 fractions or 20 Gy in five fractions in the cEBRT group, respectively. The primary end point was an improvement in the pain score at the treated site by at least 2 points (on a visual analog scale from 0 to 10 points) at 6-month follow-up. Data were analyzed on an intention-to-treat and per-protocol basis. RESULTS: Of 214 patients who were screened for eligibility, 63 were randomized 1:1 between SBRT (33 patients with 36 metastases) and cEBRT (30 patients with 31 metastases). The median age of all patients was 66 years, and 40 patients were men (63.5%). In the intention-to-treat analysis, the 6-month proportion of patients who had metastases with pain reduction by 2 or more points was significantly higher in the SBRT group versus the control group (69.4% vs. 41.9%, respectively; two-sided p = .02). Changes in opioid medication intake relative to baseline were nonsignificant between the groups. No differences were observed in vertebral compression fracture or adverse event rates between the groups. CONCLUSIONS: Dose-intensified SBRT improved pain score more effectively than cEBRT at 6 months.