Recent advances in pharmacotherapy for cancer pain management

The incidence risk of breast and gynecological cancer by antidepressant use: A systematic review and dose-response meta-analysis of epidemiological studies involving 160,727 patients

Background and objective

Antidepressants are widely prescribed to treat depression and anxiety disorders that may become chronic conditions among women. Epidemiological studies have yielded inconsistent results on the correlation between antidepressant use and the incidence risk of female breast and gynecological cancer, along with uncertain dose-response relationship. Therefore, we performed a systematic review and dose-response meta-analysis to investigate the association.

Methods

Web of Science, Embase, PubMed, The Cochrane Library, and PsycINFO were systematically searched in January 2022, with no language limits. Random-effect models were used to calculate pooled effect sizes and 95% confidence intervals between studies. Linear and non-linear dose-response analyses were performed to evaluate the dose or duration of antidepressant use affecting the incidence risk of female breast and gynecological cancer. Further subgroup analyses were systematically performed by stratifying almost all study characteristics and important potential confounders, in order to further clarify and validate the important potential hypotheses regarding the biological mechanism underlying this association.

Results

Based on a systematic literature search, 34 eligible studies (27 case-control studies and 7 cohort studies) involving 160,727 female breast and gynecological cancer patients found that antidepressant use did not increase the incidence risk of female breast and gynecological cancer (pooled OR: 1.01; 95% CI: 0.97, 1.04, I² = 71.5%, p < 0.001), and even decreased the incidence risk of ovarian cancer (pooled OR: 0.91; 95% CI: 0.83, 1, I² = 17.4%, p = 0.293). There were a non-linear dose-response relationship (p non-linearity < 0.05) between the duration of antidepressant use and incidence risk of female breast cancer, and an inverse linear dose-response relationship between antidepressant use and the incidence risk of gynecological cancer, specifically with an increase of cumulative defined daily dose or duration to a high level, like 25,550 doses (OR: 0.91, 95% CI: 0.85-0.98, p linearity < 0.05) or 4,380 days (OR: 0.82; 95% CI: 0.7, 0.96, p linearity < 0.05), compared to never antidepressant users.

Conclusion

This systematic review and dose-response meta-analysis found that antidepressant use did not increase the incidence risk of female breast and gynecological cancer and even decreased the incidence risk of ovarian cancer, along with a non-linear or linear dose-response relationship.

Systematic Review Registration

PROSPERO https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=313364, identifier CRD42022313364.

A recent development of new therapeutic agents and novel drug targets for cancer treatment

Despite recent advances in cancer diagnosis, prevention, detection, as well as management, the disease is expected to be the top cause of death globally. The chemotherapy approach for cancer has become more advanced in its design, yet no medication can cure enough against all types of cancer and its stage. Thus, this review aimed to summarize a recent development of new therapeutic agents and novel drug targets for the treatment of cancer. Several obstacles stand in the way of effective cancer treatment and drug development, including inaccessibility of tumor site by appropriate drug concentration, debilitating untoward effects caused by non-selective tissue distribution of chemotherapeutic agents, and occurrence of drug resistance, which leads to cross-resistance to a variety of drugs. Resistance to treatment with anticancer drugs results from multiple factors and the most common reason for acquiring drug resistance is marking and expelling drugs that prevent cancer cells to be targeted by chemotherapeutic agents. Moreover, insensitivity to drug-induced apoptosis, alteration, and mutation of drug target and interference/change of DNA replication are other main causes of treatment failure.

PI3Kγ/AKT Signaling in High Molecular Weight Hyaluronan (HMWH)-Induced Anti-Hyperalgesia and Reversal of Nociceptor Sensitization

High molecular weight hyaluronan (HMWH), a well-established treatment for osteoarthritis pain, is anti-hyperalgesic in preclinical models of inflammatory and neuropathic pain. HMWH-induced anti-hyperalgesia is mediated by its action at cluster of differentiation 44 (CD44), the cognate hyaluronan receptor, which can signal via phosphoinositide 3-kinase (PI3K), a large family of kinases involved in diverse cell functions. We demonstrate that intrathecal administration of an oligodeoxynucleotide (ODN) antisense to mRNA for PI3Kγ (a Class I PI3K isoform) expressed in dorsal root ganglia (DRGs), and intradermal administration of a PI3Kγ-selective inhibitor (AS605240), markedly attenuates HMWH-induced anti-prostaglandin E₂ (PGE₂) hyperalgesia, in male and female rats. Intradermal administration of inhibitors of mammalian target of rapamycin (mTOR; rapamycin) and protein kinase B (AKT; AKT Inhibitor IV), signaling molecules downstream of PI3Kγ, also attenuates HMWH-induced anti-hyperalgesia. In vitro patch-clamp electrophysiology experiments on cultured nociceptors from male rats demonstrate that some HMWH-induced changes in generation of action potentials (APs) in nociceptors sensitized by PGE₂ are PI3Kγ dependent (reduction in AP firing rate, increase in latency to first AP and increase in slope of current ramp required to induce AP) and some are PI3Kγ independent [reduction in recovery rate of AP afterhyperpolarization (AHP)]. Our demonstration of a role of PI3Kγ in HMWH-induced anti-hyperalgesia and reversal of nociceptor sensitization opens a novel line of research into molecular targets for the treatment of diverse pain syndromes.SIGNIFICANCE STATEMENT We have previously demonstrated that high molecular weight hyaluronan (HMWH) attenuates inflammatory hyperalgesia, an effect mediated by its action at cluster of differentiation 44 (CD44), the cognate hyaluronan receptor, and activation of its downstream signaling pathway, in nociceptors. In the present study, we demonstrate that phosphoinositide 3-kinase (PI3K)γ and downstream signaling pathway, protein kinase B (AKT) and mammalian target of rapamycin (mTOR), are crucial for HMWH to induce anti-hyperalgesia.

The history of cancer pain and bone-targeted agents: 10 most commonly asked questions

The prevalence of pain and skeletal complications of metastatic bone disease is high and an important factor, which contributes to decreased quality of life and low survival rate. Bone-targeted agents are well-established therapies to reduce the skeletal-related events in patients with bone metastasis. However, the analgesic effect of these medications is still controversial. The objective of this review is to summarize the existing evidence about the use of bone-targeted agents in the treatment of metastatic bone pain, trying to answer to the 10 most commonly asked questions in this matter. To achieve this goal, authors did a research of reviews published between January 2001 and January 2018, using the terms MeSH: “cancer pain” and bisphosphonates. The source used was the PubMed (NLM) database. The search yielded 36 reviews, but only 16 met the inclusion criteria. Even with the introduction of a new class of drugs, bisphosphonates and specially zoledronic acid are the most commonly used drugs in most oncology centers. Bisphosphonates and denosumab appear to be beneficial in preventing skeletal morbidity but their analgesic role and impact on quality of life and survival are not so well established.

Revealing brain mechanisms of mTOR-mediated translational regulation: Implications for chronic pain

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mTOR is a major regulator of protein translation.

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mTOR serves an important role in neural plasticity.

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mTOR signalling in the brain as a pathology for neurological disorder is known.

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mTOR signalling in the brain as a chronic pain mechanism is understudied.

In the spinal cord, altered protein transcription and translation have received a lot of recent attention for their role in neural plasticity, a major mechanism leading to the development of chronic pain. However, changes in brain plasticity are also associated with the maintenance of pain symptoms, but these cellular mechanisms remain less clear. The mechanistic/mammalian target of rapamycin (mTOR) is a master regulator of protein synthesis, and controls several neuronal functions, including neural plasticity. While aberrant changes in mTOR signaling are associated with sensitization of the pain pathway (sensory neurons and spinal cord), there are various nervous system diseases that have pain as a comorbidity and altered mTOR activity in the brain. Here, we provide a brief review of mTOR changes in the brain that are associated with some neurological disorders and focus on how these changes may be relevant to the pain of the underlying condition and chronic pain itself.

Psychotropic Drugs in Terminally Ill Patients: A Review of the Clinical and Research Literature

The principal psychopharmacological drugs used with terminally ill persons were briefly reviewed, and special consideration for various terminal illnesses were discussed. Sections on the analgesic effects of psychotropic drugs, the psychotropic properties of opioids, the beneficial effects of marijuana, and the use of LSD in terminal cancer patients are included.

Celecoxib Versus Diclofenac in Mild to Moderate Depression Management Among Breast Cancer Patients: A Double-Blind, Placebo-Controlled, Randomized Trial

BACKGROUND

Depression is a well-known complication of breast cancer, which is known to adversely affect quality of life, prognosis, and survival in breast cancer patients. Celecoxib, a nonsteroidal anti-inflammatory drug, which acts via the selective inhibition of cyclo-oxygenase (COX)-2, has been shown to have antidepressive effects.

OBJECTIVES

Here, we aimed to compare the efficacy and safety of celecoxib, a selective inhibitor of COX-2, with diclofenac, a nonselective inhibitor of both COX-1 and COX-2 in reducing depressive symptoms and pain in breast cancer patients.

METHODS

A total of 52 outpatients with breast cancer with mild to moderate depression, who suffered from pain and needed analgesics, participated in the trial and underwent 6 weeks of treatment with either celecoxib (200 mg twice daily) or diclofenac (50 mg twice daily). Participants were investigated using the Hamilton Depression Rating Scale (HDRS). The primary outcome measure was to compare the antidepressant effects of celecoxib and diclofenac.

RESULTS

Repeated-measures analysis demonstrated significant effect for Time × Treatment interaction on the HDRS scores: F(1.76, 87.85) = 9.66; P < 0.001. By study conclusion, greater improvement was observed in the HDRS score of the celecoxib group compared with the diclofenac group (P = 0.002). No one experienced remission (HDRS ≤ 7) in either group. Frequencies of adverse events were not significantly different between groups.

CONCLUSION

Celecoxib seems to possess superior antidepressive effects compared with diclofenac in breast cancer patients with mild to moderate depression.

mTOR, a new potential target for chronic pain and opioid-induced tolerance and hyperalgesia

Chronic pain is a major public health problem with limited treatment options. Opioids remain a routine treatment for chronic pain, but extended exposure to opioid therapy can produce opioid tolerance and hyperalgesia. Although the mechanisms underlying chronic pain, opioid-induced tolerance, and opioid-induced hyperalgesia remain to be uncovered, mammalian target of rapamycin (mTOR) is involved in these disorders. The mTOR complex 1 and its triggered protein translation are required for the initiation and maintenance of chronic pain (including cancer pain) and opioid-induced tolerance/hyperalgesia. Given that mTOR inhibitors are FDA-approved drugs and an mTOR inhibitor is approved for the treatment of several cancers, these findings suggest that mTOR inhibitors will likely have multiple clinical benefits, including anticancer, antinociception/anti-cancer pain, and antitolerance/hyperalgesia. This paper compares the role of mTOR complex 1 in chronic pain, opioid-induced tolerance, and opioid-induced hyperalgesia.

Lentivirus mediated siRNA against GluN2B subunit of NMDA receptor reduces nociception in a rat model of neuropathic pain

Although neuropathic pain (NP) is still not fully understood by scientists and clinicians alike, studies suggest that N-methyl-D-aspartate (NMDA) receptors play an important role in the induction and maintenance of NP. A promising treatment for NP is through the downregulation of NMDA subunit GluN2B by RNA interference; however, naked siRNA (small interference RNA) is not effective in long-term treatments. In order to concoct a viable prolonged treatment for NP, Lv-siGluN2B (lentivirus carrying siRNA targeting GluN2B subunit) was prepared and the antinociception effects were observed in chronic constriction injury (CCI) rats in the present study. Results showed that Lv-siGluN2B was transduced into spinal cord cells after intrathecal injections and effectively reduced the nociception induced by sciatic nerve ligation while inhibiting the mRNA and protein expression of GluN2B. This antinociception effect lasted approximately 7 weeks. These findings suggest that GluN2B subunit could be a target for NP treatment and Lv-siGluN2B represents a new potential option for long-term treatment of NP.

Effects of Metastasis on Pain Treatment in Patients with Cancer-Related Pain: A Retrospective Study

OBJECTIVE

The goal of this study was to investigate the effect of the presence of metastases on pain treatment in patients with cancer-related pain.

METHODS

Of the 1736 patients who were treated in Firat University, Faculty of Medicine, Department of Anaesthesiology and Reanimation, Algology Section, for cancer-related pain between January 1997 and December 2010, 1467 with complete medical records were evaluated. Patients were grouped as having no metastasis (Group I), a single organ metastasis (Group II), or multiple organ metastasis (Group III).

RESULTS

There was no difference between the groups with regard to age. Visual Analog Pain (VAS) scores at admission were higher in Group III compared to the other groups, and significantly higher in Group I than in Group II. Analgesic ladder treatment was given to 85.5% of patients, and 14.5% were treated using additional minimally invasive analgesic intervention (MIAI) methods. In Group II and Group III, the rates of treatment in Step I and II were lower compared to Group I, while the rates of treatment in Step III were higher. Implementation of MIAI was higher in Group III than in the other groups, and higher in Group II than in Group I.

CONCLUSION

The presence of metastases causes more severe pain, which becomes more difficult to treat, and increases the analgesia step and the consumption of opioids in patients with cancer-related pain.

Spinal cord NMDA receptor-mediated activation of mammalian target of rapamycin is required for the development and maintenance of bone cancer-induced pain hypersensitivities in rats

Mammalian target of rapamycin (mTOR) controls mRNA translation and is critical for neuronal plasticity. However, how it participates in central sensitization underlying chronic pain is unclear. Here, we show that NMDA receptors are required for the functional role of spinal cord mTOR in bone cancer pain induced by injecting prostate cancer cells (PCCs) into the tibia. Intrathecal rapamycin, a specific mTOR inhibitor, dose dependently attenuated the development and maintenance of PCC-induced mechanical allodynia and thermal hyperalgesia. Rapamycin alone did not affect locomotor activity and acute responses to thermal or mechanical stimuli. Phosphorylation of mTOR and p70S6K (a downstream effector) was increased time dependently in L(4-5) dorsal horn and transiently in L(4-5) dorsal root ganglions on the ipsilateral side after PCC injection, although total expression of mTOR or p70S6K was not changed in these regions. The increases in dorsal horn were abolished by intrathecal infusion of DL-AP5, an NMDA receptor antagonist. Moreover, NMDA receptor subunit NR1 colocalized with mTOR and p70S6K in dorsal horn neurons. These findings suggest that PCC-induced dorsal horn activation of the mTOR pathway participates in NMDA receptor-triggered dorsal central sensitization under cancer pain conditions.

PERSPECTIVE

The present study shows that inhibition of spinal mTOR blocks cancer-related pain without affecting acute pain and locomotor function. Given that mTOR inhibitors are FDA-approved drugs, mTOR in spinal cord may represent a potential new target for preventing and/or treating cancer-related pain.

Cancer Pain: A Critical Review of Mechanism-based Classification and Physical Therapy Management in Palliative Care

Mechanism-based classification and physical therapy management of pain is essential to effectively manage painful symptoms in patients attending palliative care. The objective of this review is to provide a detailed review of mechanism-based classification and physical therapy management of patients with cancer pain. Cancer pain can be classified based upon pain symptoms, pain mechanisms and pain syndromes. Classification based upon mechanisms not only addresses the underlying pathophysiology but also provides us with an understanding behind patient's symptoms and treatment responses. Existing evidence suggests that the five mechanisms – central sensitization, peripheral sensitization, sympathetically maintained pain, nociceptive and cognitive-affective – operate in patients with cancer pain. Summary of studies showing evidence for physical therapy treatment methods for cancer pain follows with suggested therapeutic implications. Effective palliative physical therapy care using a mechanism-based classification model should be tailored to suit each patient's findings, using a biopsychosocial model of pain.

Orofacial pain in cancer: part II--clinical perspectives and management

Cancer-associated pain is extremely common and is associated with significant physical and psychological suffering. Unfortunately, pain associated with cancer or its treatment is frequently under-treated, probably due to several factors, including phobia of opioids, under-reporting by patients, and under-diagnosis by healthcare workers. The most common etiology of cancer pain is local tumor invasion (primary or metastatic), involving inflammatory and neuropathic mechanisms; these have been reviewed in Part I. As malignant disease advances, pain usually becomes more frequent and more intense. Additional expressions of orofacial cancer pain include distant tumor effects, involving paraneoplastic mechanisms. Pain secondary to cancer therapy varies with the treatment modalities used: Chemo-radiotherapy protocols are typically associated with painful mucositis and neurotoxicity. Surgical therapies often result in nerve and tissue damage, leading, in the long term, to myofascial and neuropathic pain syndromes. In the present article, we review the clinical presentation of cancer-associated orofacial pain at various stages: initial diagnosis, during therapy (chemo-, radiotherapy, surgery), and in the post-therapy period. As a presenting symptom of orofacial cancer, pain is often of low intensity and diagnostically unreliable. Diagnosis, treatment, and prevention of pain in cancer require knowledge of the presenting characteristics, factors, and mechanisms involved.

Barriers to pain management in the rehabilitation of the surgical oncology patient

Virtually every surgical oncology patient faces pain, and it can become a major barrier to rehabilitation and quality of life. Pain must be assessed as to its severity, etiology (somatic, visceral, or neuropathic), causation (directly from malignancy or from treatment side effects), and its impact on daily function. Treatments can include physical modalities, exercise, opioids, adjuvant medications, and interventional techniques. Barriers to treatment may include side effects, finances, and attitudes. New technologies in medication delivery systems, intrathecal pumps, injections, and surgery have greatly strengthened the armamentarium available to manage pain.

Cancer pain in palliative care: why is management so difficult?

Pain is the major source of anxiety and distress at the end of life, particularly in cases of end-stage cancer. However, pain management is not always effective or effectively implemented. This article identifies several barriers to effective pain relief in terminal cancer--the complexity of pain; difficulties in physical, emotional and spiritual assessment; difficulties in the delivery of medication--that challenge the skills of all professionals involved in palliative care. There are no simple answers, but awareness of the breadth of the issues may help focus nurses' minds on the patient in every encounter.

Antidepressant Medication Use for and Risk of Ovarian Cancer

OBJECTIVE

It has been hypothesized that antidepressants may enhance cancer growth. Previous studies of antidepressant use and ovarian cancer have been inconsistent and have been limited in their ability to examine the association with selective serotonin reuptake inhibitors (SSRIs), which are currently the antidepressants most commonly prescribed. The objective of this paper was to evaluate whether women with ovarian cancer were more likely to report past use of antidepressants than control women.

METHODS

Antidepressant use was assessed in a population-based, case-control study of ovarian cancer (593 cases, 628 controls). Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) associated with antidepressant use overall and by subcategories of antidepressants.

RESULTS

Antidepressant use was reported by 18% of cases and 20% of controls. No increased risk was observed for ever use of any type of antidepressant (OR 0.9, 95% CI 0.7-1.2) or for SSRIs (OR 1.0, 95% CI 0.7-1.5). There also was no evidence of increased risk with longer duration of use. Our study had greater than 80% power to detect an OR as small as 1.5. Thus, even a modest increase in risk associated with antidepressant use can be excluded with these data.

CONCLUSION

Our study adds to the growing body of evidence suggesting that antidepressants do not have a significant effect on ovarian cancer risk. In particular, the data suggest that SSRIs, which are the most commonly used class of antidepressants, are not associated with an increased risk for ovarian cancer.

LEVEL OF EVIDENCE

II-2.

Managing breakthrough pain: a clinical review with three case studies using oral transmucosal fentanyl citrate

Pain management begins with the use of appropriate assessment tools and includes planning, implementing, and evaluating a comprehensive treatment plan that addresses persistent and breakthrough pain. Persistent pain is present to some degree throughout the day and primarily is controlled with around-the-clock medication. However, it often is accompanied by episodes of short, intermittent pain, also known as breakthrough pain. From a clinical perspective, breakthrough pain is characterized as a transitory exacerbation of pain that occurs on a background of otherwise stable pain in a patient receiving chronic opioid therapy. Breakthrough pain typically is moderate to severe in intensity and can be triggered by various activities (incident pain), be entirely unpredictable (idiopathic pain), or occur toward the end of around-the-clock medication (end-of-dose failure). Breakthrough pain occurs in as many as 86% of patients with cancer even when persistent pain is well controlled. Clinicians and patients should address persistent and breakthrough pain as distinct entities to accurately assess it and develop appropriate pain management plans. This article provides an overview of the clinical characteristics of persistent and breakthrough pain and, through the use of three case studies, illustrates practical strategies for managing breakthrough pain effectively.

Efficacy and Safety of Ibandronate in the Treatment of Opioid-Resistant Bone Pain Associated With Metastatic Bone Disease: A Pilot Study

Purpose

Bone metastases are associated with severe and sometimes intractable pain, compromising patient quality of life (QOL). This open-label pilot study investigated the effects of short-term intensive treatment with intravenous (IV) ibandronate on opioid-resistant bone pain in patients with skeletal metastases.

Patients and Methods

Eighteen patients with advanced tumors and metastatic bone disease received nonstandard treatment with 4 mg of ibandronate administered IV (2-hour infusion) for 4 consecutive days (16-mg total dose). Baseline opioid analgesic use was equivalent to 400 mg/d of morphine. Patients were assessed for 6 weeks or until death. Changes from baseline were determined for bone pain, opioid consumption, patient functioning, QOL, performance status, and biochemical markers of calcium metabolism and bone turnover. Renal function was assessed by serum urea and creatinine measurement.

Results

Short-term, intensive ibandronate treatment significantly reduced bone pain scores within 7 days (P < .001). Pain reductions were sustained over the study period. Ibandronate significantly improved QOL, patient functioning, and performance status (P < .05). Mean values of the urinary cross-links pyridinoline and deoxypyridinoline tended to increase after day 21, returning close to baseline values by day 42. There was no correlation between the change in crosslinks values and the change in pain scores after ibandronate treatment. Ibandronate was well tolerated, with no evidence of renal toxicity.

Conclusion

Nonstandard, intensive treatment with IV ibandronate seems to have a marked analgesic effect in patients with opioid-resistant bone pain from metastatic bone disease. Further investigation is warranted.

Managing pain in mucositis

OBJECTIVE

To discuss pharmacologic and nonpharmacologic approaches available to manage pain.

DATA SOURCE

Published journal articles, book chapters, clinical experience.

CONCLUSION

Pain management requires treatment directed at the various factors involved in the pain experience.

IMPLICATIONS FOR NURSING PRACTICE

Nurses need to assess pain daily and follow patients closely until mucositis resolves. Management targeted to specific dimensions of pain can improve the effectiveness of pain control.