Two guidelines about opioid use in chronic pain management were published in 2017: the Canadian Guideline for Opioids for Chronic Non-Cancer Pain and the European Pain Federation position paper on appropriate opioid use in chronic pain management. Though the target populations for the guidelines are the same, their recommendations differ depending on their purpose. The intent of the Canadian guideline is to reduce the incidence of serious adverse effects. Its goal was therefore to set limits on the use of opioids. In contrast, the European Pain Federation position paper is meant to promote safe and appropriate opioid use for chronic pain.     The content of the two guidelines could have unintentional consequences on other populations that receive opioid therapy for symptom management, such as patients with cancer. In this article, we present expert opinion about those chronic pain management guidelines and their impact on patients with cancer diagnoses, especially those with histories of substance use disorder and psychiatric conditions. Though some principles of chronic pain management can be extrapolated, we recommend that guidelines for cancer pain management should be developed using empirical data primarily from patients with cancer who are receiving opioid therapy.

Objective : We performed a systematic review to quantify the cardiovascular risk of adjuvant radiotherapy (RT) for breast cancer. Methods: A literature search was conducted using MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials from inception to July 2020. Results: The literature search produced 7363 reports, of which 76 met our inclusion criteria. In studies comparing left-sided RT with right-sided RT, 7 of 35 (20%) studies found increased cardiovascular mortality, and 8 of 28 (29%) studies found increased cardiovascular events. In studies comparing patients who received RT with those who did not, 7 of 26 (27%) studies found increased cardiovascular mortality, and 5 of 22 (23%) studies found increased cardiovascular events. Conclusion:Most of the studies that found significant associations between laterality and cardiovascular risks included treatment periods that started prior to 1985, suggesting that modern RT techniques have minimised the cardiac exposure in breast cancer patients receiving RT. However, more focused studies must be conducted to investigate the long-term cardiovascular risk associated with modern RT techniques.