Pharmacological options for the management of refractory cancer pain-what is the evidence?

Refractory cancer pain that does not respond to standard opioid and/or co-analgesic therapy occurs in 10-20 % of patients. Risk factors include young age, neuropathic pain type, incident pain, psychological distress, previous opioid use, high tolerance, a history of addiction and impaired cognition. The management of patients with refractory pain remains a challenge. Treatment options include opioid manipulation (parenteral delivery, rotation, combination, methadone and buprenorphine), non-opioids and co-analgesics (paracetamol, non-steroidal anti-inflammatory agents, antidepressants and anticonvulsants), NMDA receptor antagonists, cannabinoids, lignocaine and corticosteroids. The evidence of benefit for any of these agents is weak, and each additional agent increases the risk of adverse events. Evidence-based guidelines cannot, therefore, be developed at present. New approaches are recommended including targeted opioid therapy, multimodal analgesia, a goal-oriented approach to pain management and increasing use of the multidisciplinary team and support services.

Comparison and analysis of the animal models used to study the effect of morphine on tumour growth and metastasis.

UNLABELLED: The effect of opioids on tumour growth and metastasis has been debated for many years, with recent emphasis on the possibility that they might influence the rate of disease-free survival after tumour resection when used in the perioperative pain management of cancer surgery patients. The literature presents conflicting and inconclusive in vitro and in vivo data about the potential effect of opioids, especially morphine, on tumour growth and metastasis. To inform clinical practice, appropriate animal models are needed to test whether opioids alter the course of tumour growth and metastasis. Here, we review the literature on animal-based studies testing the effect of morphine on cancer so far, and analyse differences between the models used that may explain the discrepancies in published results. Such analysis should elucidate the role of opioids in cancer and help define ideal pre-clinical models to provide definitive answers. LINKED ARTICLES: This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.

Effect of lysine antifibrinolytics and cyclooxygenase inhibitors on the proteolytic profile of breast cancer cells interacting with macrophages or endothelial cells.

BACKGROUND: Extracellular matrix (ECM) proteases play a key role in the regulation of tumour invasion, growth, and transendothelial migration. The expression of ECM proteases and their endogenous inhibitors by cancer cells is regulated by stromal cells. We investigated the effect of commonly used perioperative medications on this regulation. METHODS: Breast cancer cells (4T1) were cultured alone or with endothelial cells (H5V) or macrophages (RAW264.7). Cell grown alone or in cocultures were treated with clinically relevant concentrations of cyclooxygenase (COX) inhibitors, aspirin (ASA), ketorolac, celecoxib, or lysine antifibrinolytics, ɛ-aminocaproic acid (EACA) and tranexamic acid (TXA). We determined the level of the ECM proteases urokinase-like plasminogen activator (uPA), matrix metalloproteinase (MMP)-2 and MMP-9, and endogenous MMP inhibitors, tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in the conditioned media. RESULTS: Antifibrinolytics and COX inhibitors exerted a complex effect on cells grown alone and in cocultures. EACA increased the activity of MMP-9 and TIMP-1 in cocultures of 4T1 and RAW264.7. TXA increased TIMP-1 in the coculture without affecting MMP-9. EACA and TXA both attenuated MMP-2 detected in 4T1 and H5V cocultures. ASA and ketorolac both decreased the activity of MMP-2, MMP-9, and uPA. Celecoxib increased the activity of TIMP-1 in cocultures of 4T1 with both macrophages and endothelial cells. CONCLUSIONS: Antifibrinolytics and COX inhibitors can affect the proteolytic profile of the tumour microenvironment. Animal and clinical investigations are warranted to assess the effect of these proteolytic changes on the outcome of cancer surgery.