Risk of second breast cancer events with chronic opioid use in breast cancer survivors

Opioids and Cancer: Current Understanding and Clinical Considerations

Pain is one of the most common symptoms in patients with cancer. Pain not only negatively affects the quality of life of patients with cancer, but it has also been associated with reduced survival. Pain management is therefore a critical component of cancer care. Prescription opioids remain the first-line approach for the management of moderate-to-severe pain associated with cancer. However, there has been increasing interest in understanding whether these analgesics could impact cancer progression. Furthermore, epidemiological data link a possible association between prescription opioid usage and cancer development. Until more robust evidence is available, patients with cancer with moderate-to-severe pain may receive opioids to decrease suffering. However, future studies should be conducted to evaluate the role of opioids and opioid receptors in specific cancers.

The influence of anaesthesia on cancer growth

BACKGROUND

Oncological patients make up a large proportion of all surgical patients. Through its influence on the patient's inflammatory and immune system, the choice of anaesthetic technique has an indirect impact on the health of the individual patient and on public health. Both the specific and the non-specific immune system have a major influence on the recurrence of carcinomas. The pathophysiological basis for growth and metastasis after surgery is the physiological response to stress. Inflammation is the organism's universal response to stress. Anaesthetics and adjuvants influence perioperative inflammation in different ways and have an indirect effect on tumour growth and metastasis. In vitro studies have shown how individual anaesthetics influence the growth and spread of cancer, but clinical studies have not confirmed these results. Nevertheless, it is advisable to use an anaesthetic that has shown lesser effect on the growth of cancer cells in vitro.

CONCLUSIONS

In this review, we focus on the area of the effects of anaesthesia on tumour growth. The field is still relatively unexplored, there are only few clinical prospective studies and their results are controversial. Based on the review of new research findings we report on recommendations about anaesthetics and anaesthetic techniques that might be preferable for oncological surgical procedures.

Impact of anesthesia on postoperative breast cancer prognosis: A narrative review

The incidence of breast cancer has exhibited an annually increasing trend, and the disease has become the most common malignant tumour worldwide. Currently, the primary treatment for breast cancer is surgical resection. However, metastatic recurrence is the main cause of cancer-related death in this patient population. Various factors are associated with breast cancer prognosis, and anaesthesia-induced changes in the tumour microenvironment have attracted increasing attention. To date, however, it remains unclear whether anaesthetic drugs have a positive or negative impact on cancer outcomes after surgery. The present article reviews the effects of different anaesthetics on the postoperative prognosis of breast cancer surgery to guide the choice of anaesthetic technique(s) and agents for such patients.

The association between perioperative opioids and breast cancer recurrence: a narrative review of the literature

Background and Objective

Opioid use disorder is an evolving crisis, and 17.2% of postsurgical patients continue to fill an opioid prescription one year after surgery. Preclinical studies suggest perioperative opioid use, defined here as opioids used in the setting of operative pain, may be linked to inferior oncologic outcomes. If this were true, opioid minimization strategies for surgical patients may reduce opioid-related deaths in more than one way. This review aims to describe the association between perioperative opioid use and breast cancer recurrence.

Methods

On November 1, 2021, we searched the Ovid and EMBASE databases for the terms "breast neoplasm", "opioid analgesics", "neoplasm recurrence", and "neoplasm metastasis". Of the 350 articles retrieved, 11 met our inclusion criteria. The review was undertaken using the enhancing transparency in reporting the synthesis of qualitative research (ENTREQ) checklist for quality.

Key Content and Findings

Clinical studies report no clear association between perioperative opioid use and local or distant breast cancer recurrence. Mixed results were found when assessing perioperative opioid use and overall survival. Multiple studies paradoxically found opioid use to be associated with lower recurrence rates, despite higher mortality rates. Most studies showed no difference in recurrence or survival in breast cancer surgery patients who did or did not receive opioid-containing analgesia, although most findings were limited by study design and low event rates in patients with breast cancer.

Conclusions

The lack of a clear connection between perioperative opioid use and breast cancer recurrence contradicts some preclinical data, which describes mechanisms through which opioids upregulate tumor proliferation which might worsen oncologic outcomes. Existing clinical literature is limited to mostly retrospective studies in patients with predominantly early-stage breast cancers, with low event rates. Given the worsening opioid epidemic and preclinical study findings, opioid minimization strategies should still be explored. Future work should be prospective and examine cancer recurrence in high-risk patients with more advanced tumor pathologies.

Integrative Surgery: Embedding Complementary and Nonpharmacologic Therapies into Surgical Pain Management Strategies

There has been a growing interest in the use of complementary and alternative medicine in modern pain management strategies on behalf of both patients and clinicians. Nonpharmacologic modalities such as cryotherapy, acupuncture, music, and mind-body therapies have been shown to aid in symptom control and improve quality of life in patients suffering from acute and chronic pain, and there is a growing body of literature demonstrating their feasibility, acceptability, and efficacy in the perioperative period. Here, we provide a brief review of the current evidence supporting the use of complementary therapies within existing perioperative pain management strategies and highlight evidence-based protocols to facilitate implementation into modern surgical practice.

The other side of the coin: Positive view on the role of opioids in cancer

Opioids have been used for medicinal purposes as an analgesic and recreational purposes as a euphorigenic throughout human history. Cancer patients are often treated with different doses of opioids concurrently with anti-cancer drugs for pain relief without exhibiting excessive adverse effects. The intersection of the biology of pain, opioid therapy, and disease progression represents the crux of the matters and is of potentially great importance in cancer care. For more than 20 years, multiple investigations have focused on the stimulatory effects of opioids on cancer cell growth, while in-depth studies on the inhibitory effects on cancer cell growth development have usually been neglected. This paper reviews the evidence regarding opioid therapies and their anti-cancer effects on various malignancies. Likewise, we have a glimpse into the molecular mechanisms necessary for pinpointing their positive or negative impacts on malignancies to raise awareness and stimulate more excellent dialogue regarding their carcinogenic/anticarcinogenic roles.

Opioid Prescribing and Use Among Cancer Survivors: A Mapping Review of Observational and Intervention Studies

CONTEXT

Recent years show a sharp increase in research on opioid use among cancer survivors, but evidence syntheses are lacking, leaving knowledge gaps. Corresponding research needs are unclear.

OBJECTIVES

To provide an evidence synthesis.

METHODS

We searched PubMed and Embase, identifying articles related to cancer, and opioid prescribing/use published through September 2020. We screened resulting titles/abstracts. Relevant studies underwent full-text review. Inclusion criteria were quantitative examination of and primary focus on opioid prescribing or use, and explicit inclusion of cancer survivors. Exclusion criteria included end-of-life opioid use and opioid use as a secondary or downstream outcome (for intervention studies). We extracted information on the opioid-related outcome(s) examined (including definitions and terminology used), study design, and methods.

RESULTS

Research returned 16,591 articles; 296 were included. Only 22 of 296 studies evaluated an intervention. There were 105 studies evaluating outcomes indicative of potentially high-risk, nonrecommended, or avoidable opioid use, e.g., continuous use-described as chronic use, prolonged use, and persistent use (n = 17); use after completion of curative-intent treatment-described as chronic opioid use, long-term opioid use, persistent opioid use, prolonged opioid use, continued opioid use, late opioid use, post-treatment opioid use (n = 27); use of opioids concurrent with other potentially high-risk medications (n = 13), and opioid misuse (n = 14).

CONCLUSIONS

We found lack of consistency in the measurement of and terms used to describe similar opioid use outcomes, and a lack of interventional research targeting well-documented patterns of potentially nonrecommended, potentially avoidable, or potentially high-risk opioid prescribing or use.

Antitumor Anesthetic Strategy in the Perioperatory Period of the Oncological Patient: A Review

The stress response triggered by the surgical aggression and the transient immunosuppression produced by anesthetic agents stimulate the inadvertent dispersion of neoplastic cells and, paradoxically, tumor progression during the perioperative period. Anesthetic agents and techniques, in relation to metastatic development, are investigated for their impact on long-term survival. Scientific evidence indicates that inhaled anesthetics and opioids benefit immunosuppression, cell proliferation, and angiogenesis, providing the ideal microenvironment for tumor progression. The likely benefit of reducing their use, or even replacing them as much as possible with anesthetic techniques that protect patients from the metastatic process, is still being investigated. The possibility of using "immunoprotective" or "antitumor" anesthetic techniques would represent a turning point in clinical practice. Through understanding of pharmacological mechanisms of anesthetics and their effects on tumor cells, new perioperative approaches emerge with the aim of halting and controlling metastatic development. Epidural anesthesia and propofol have been shown to maintain immune activity and reduce catecholaminergic and inflammatory responses, considering the protective techniques against tumor spread. The current data generate hypotheses about the influence of anesthesia on metastatic development, although prospective trials that determinate causality are necessary to make changes in clinical practice.

Opioids and Breast Cancer Recurrence: A Systematic Review

Breast cancer has the greatest epidemiological impact in women. Opioids represent the most prescribed analgesics, both in surgical time and in immediate postoperative period, as well as in chronic pain management as palliative care. We made a systematic review analyzing the literature's evidence about the safety of opioids in breast cancer treatment, focusing our attention on the link between opioid administration and increased relapses. The research has been conducted using the PubMed database. Preclinical studies, retrospective and prospective clinical studies, review articles and original articles were analyzed. In the literature, there are several preclinical in vitro and in vivo studies, suggesting a possible linkage between opioids administration and progression of cancer disease. Nevertheless, these results are not confirmed by clinical studies. The most recent evidence reassures the safety of opioids during surgical time as analgesic associated with anesthetics drugs, during postoperative period for optimal cancer-related pain management and in chronic use. Currently, there is controversial evidence suggesting a possible impact of opioids on breast cancer progression, but to date, it remains an unresolved issue. Although there is no conclusive evidence, we hope to arouse interest in the scientific community to always ensure the best standards of care for these patients.

Targeting the mu-Opioid Receptor for Cancer Treatment

PURPOSE OF REVIEW

Opioids are still the most effective and widely used treatments for acute and chronic pain in cancer patients. This review focuses on the impact of opioids and mu-opioid receptors (MOR) on tumor progression and providing new ideas for targeting the MOR in cancer treatment.

RECENT FINDINGS

Studies estimated that opioids facilitate tumor progression and are related to the worse prognosis in cancer patients. As the primary receptor of opioids, MOR is involved in the regulation of malignant transformation of tumors and participating in proliferation, invasion, metastasis, and angiogenesis. MOR may be a new molecular marker of malignant tumors and thus become a new target for cancer therapy, which may be beneficial to the outcomes of cancer patients.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Variations in Long-term Opioid Therapy Definitions: A Systematic Review of Observational Studies Using Routinely Collected Data (2000-2019)

Routinely collected data have been increasingly used to assess long-term opioid therapy (LTOT) patterns, with very little guidance on how to measure LTOT from these data sources. We conducted a systematic review of studies published between January 2000 and July 2019 to catalogue LTOT definitions, the rationale for definitions and LTOT rates in observational research using routinely collected data in nonsurgical settings. We screened 4056 abstracts, 210 full-text manuscripts and included 128 studies, mostly from the United States (81%) and published between 2015 and 2019 (69%). We identified 78 definitions of LTOT, commonly operationalised as 90 days of use within a year (23%). Studies often used multiple criteria to derive definitions (60%), mostly based on measures of duration, such as supply days/days of use (66%), episode length (21%) or prescription fills within specified time periods (12%). Definitions were based on previous publications (63%), clinical judgment (16%) or empirical data (3%); 10% of studies applied more than one definition. LTOT definition was not provided with enough details for replication in 14 studies and 38 studies did not specify the opioids evaluated. Rates of LTOT within study populations ranged from 0.2% to 57% according to study design and definition used. We observed a substantial rise in the last 5 years in studies evaluating LTOT with large variability in the definitions used and poor reporting of the rationale and implementation of definitions. This variation impacts on research reproducibility, comparability of findings and the development of strategies aiming to curb therapy that is not guideline-recommended.

Anaesthesia as an influence in tumour progression

Purpose

Tumour growth and the formation of metastases are essential elements in the progression of cancer. The centre of treatment is the surgical resection of primary solid tumours. But even if the tumour can be removed without microscopic residual cells, local recurrences and distant metastases occur and determine the patient’s fate. During the operation, tumour cells are shed from the primary tumour and released into the circulation. These circulating tumour cells might play an important role in the formation of new tumour sites. Therefore, a functional innate and adaptive immune system is essential, especially in this perioperative period. Anaesthesia influences consciousness and pain perception and interacts directly with the immune system and tumour cells.

Methods

Review of the current literature concerning intra- and postoperative anaesthetic decisions and tumour progression.

Results

There are beneficial aspects for patient survival associated with total intravenous anaesthesia, the use of regional anaesthetics and the avoidance of allogeneic red blood cell transfusions. Alternatives such as irradiated intraoperative blood salvage and preoperative iron supplementation may be advantageous in cases where transfusions are limited or not wanted. The immunosuppressive properties of opioids are theoretical, but strong evidence to avoid them does not exist. The application of nonsteroidal anti-inflammatory drugs and postoperative nausea and vomiting prophylaxis do not impair the patient’s survival and may even have a positive effect on tumour regression.

Conclusion

Anaesthesia does play an important part in the perioperative period in order to improve the cancer-related outcome. Further research is necessary to make more concrete recommendations.

Opioids and cancer prognosis: A summary of the clinical evidence

Pain is a common and devastating symptom among cancer patients. It can be caused by the cancer itself or by certain therapies like surgery, radiation or chemotherapy. Opioids are the first line of treatment for moderate to severe cancer-related pain. Opioids alone or in combination with non-opioid analgesics and adjuvant medications are important components for pain management during the perioperative period for cancer patients. Opioids act on the μ-opioid receptor (MOR), which is expressed in cancer cells and non-malignant cells of the tumor microenvironment. Retrospective studies suggest an association between the expression of MOR in cancers and shorter survival. In addition, recent evidence suggests that opium use and prescription opioids can influence clinical oncological outcomes. In this review, we will summarize the clinical evidence regarding the effect of opioid administration and survival in patients with cancer as well as the current evidence involving MOR expression and cancer progression.

Chronic Opioid Use and Risk of Cancer in Patients with Chronic Noncancer Pain: A Nationwide Historical Cohort Study

BACKGROUND

To investigate whether chronic opioid therapy is associated with a higher risk of cancer among noncancer patients with chronic pain.

METHODS

A population-based historical cohort study of the South Korean adult population was conducted using data from the National Health Insurance Service. We included patients registered with a diagnostic code of M00-M99 (musculoskeletal system and connective tissue diseases) according to the International Classification of Diseases, 10th revision, in 2010. Patients prescribed a continuous supply of any opioid drug for ≥90 days were defined as chronic opioid users.

RESULTS

A total of 351,701 patients were analyzed. Among them, 25,153 (7.2%) were chronic opioid users. Using a multivariate time-dependent Cox regression model, the risk of cancer in chronic opioid users was 1.20-fold higher than that in controls [HR, 1.20; 95% confidence interval (CI), 1.15-1.25; P < 0.001]. On subgroup analysis according to opioid potency, the cancer risk in chronic weak and strong opioid users was 1.18-fold (HR, 1.18; 95% CI, 1.13-1.23; P < 0.001) and 1.32-fold (HR, 1.32; 95% CI, 1.10-1.59; P = 0.003) higher than that in controls, respectively.

CONCLUSIONS

Chronic opioid therapy was associated with an increased risk of cancer among noncancer patients with chronic pain. This association was more evident in chronic strong opioid users. However, as unmeasured and potential confounders may have affected the results, the relationship between chronic opioid use and cancer risk should be evaluated with caution.

IMPACT

Chronic opioid therapy was associated with an increased risk of cancer among noncancer patients.

Oral analgesic use in postmenopausal women after curative breast cancer treatment: post hoc analysis of the ATAC trial

Aim: To evaluate analgesic use and associated conditions in postmenopausal women who had undergone curative breast cancer treatment. Materials & methods: This post hoc analysis used the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial database, which included patient reports of concomitant medications and associated indications during follow-up. Results: Of 3434 women with eligible concomitant medication data, 71.8% reported oral analgesic use. Of 2321 patients using analgesics ≥30 days, 47.9% reported opioid use. Musculoskeletal pain was the most common indication for oral analgesic use. Of patients using opioids, 28.1% reported concomitant laxative use. Conclusion: Approximately half of the patients reported opioid use, most commonly for noncancer (musculoskeletal) pain, suggesting that breast cancer survivors experience chronic pain that should be appropriately managed.

Patient-level factors associated with chronic opioid use in cancer: a population-based cohort study

PURPOSE

Concerns around chronic opioid use (COU), misuse, and harms have led to increased scrutiny of opioid prescribing in oncology. There is lack of research examining patient-level factors associated with COU. Our aim was to examine patient-level factors associated with COU in newly diagnosed cancer patients.

METHODS

Population-based retrospective cohort study using administrative health data of patients in Alberta, Canada, diagnosed between February 2016 and October 2017. Adult cancer patients who completed a symptom survey within ± 60 days of diagnosis were included. Patients were divided into two groups: COU (defined as continuous opioid prescriptions for at least 90 days post-diagnosis) and non-chronic opioid use (NCOU). Logistic regression was used to evaluate factors associated with COU.

RESULTS

We included 694 patients (mean age 65 years; 51% female). Most had breast (20%), colorectal (13%), and lung (33%) cancers. Of the 14% with COU, 79% were opioid naïve at diagnosis. Those in the COU group were more often diagnosed with advanced cancer (66% versus 40%), had lung cancer (47%), and were opioid tolerant (> 90 days of continuous opioids within one-year pre-diagnosis). A total of 64% of COU versus 27% of NCOU had moderate to severe pain at diagnosis (p < 0.001). Irrespective of treatment type or stage, those with moderate to severe pain, were opioid tolerant at diagnosis, or had multiple prescribers were at greater risk for COU.

CONCLUSIONS

Specific patient groups were at increased risk of COU and should be the focus of adaptive prescribing approaches to ensure that opioid use is appropriate.