Perioperative pain, analgesics and cancer-related outcomes: where do we stand?

Cancer-related pain is one of the most common and debilitating symptoms among cancer patients. Undertreated cancer-related pain interferes with daily activities and increases morbidity and mortality. While opioids continue to play an essential role in treating moderate to severe cancer-related pain, they are associated with many adverse effects including misuse. While preclinical and retrospective studies have shown a negative association between opioid use and cancer outcomes, randomized control trials demonstrate that opioid use does not influence cancer recurrence. Additionally, analgesics and adjuvants used for perioperatively or chronic pain control are unlikely to improve oncological outcomes. This article focuses on the pharmacological management of cancer-related pain and offers an overview regarding the use of these medications perioperatively and the cancer outcomes.

Opioids and premature biochemical recurrence of prostate cancer: a randomised prospective clinical trial.

BACKGROUND: Prostate cancer is one of the most prevalent neoplasms in male patients, and surgery is the main treatment. Opioids can have immune modulating effects, but their relation to cancer recurrence is unclear. We evaluated whether opioids used during prostatectomy can affect biochemical recurrence-free survival. METHODS: We randomised 146 patients with prostate cancer scheduled for prostatectomy into opioid-free anaesthesia or opioid-based anaesthesia groups. Baseline characteristics, perioperative data, and level of prostate-specific antigen every 6 months for 2 yr after surgery were recorded. Prostate-specific antigen >0.2 ng ml-1 was considered biochemical recurrence. A survival analysis compared time with biochemical recurrence between the groups, and a Cox regression was modelled to evaluate which variables affect biochemical recurrence-free survival. RESULTS: We observed 31 biochemical recurrence events: 17 in the opioid-free anaesthesia group and 14 in the opioid-based anaesthesia group. Biochemical recurrence-free survival was not statistically different between groups (P=0.54). Cox regression revealed that biochemical recurrence-free survival was shorter in cases of obesity (hazard ratio [HR] 1.63, confidence interval [CI] 0.16-3.10; p=0.03), high D'Amico risk (HR 1.58, CI 0.35-2.81; P=0.012), laparoscopic surgery (HR 1.6, CI 0.38-2.84; P=0.01), stage 3 tumour pathology (HR 1.60, CI 0.20-299) and N1 status (HR 1.34, CI 0.28-2.41), and positive surgical margins (HR 1.37, CI 0.50-2.24; P=0.002). The anaesthesia technique did not affect time to biochemical recurrence (HR -1.03, CI -2.65-0.49; P=0.18). CONCLUSIONS: Intraoperative opioid use did not modify biochemical recurrence rates and biochemical recurrence-free survival in patients with intermediate and high D'Amico risk prostate cancer undergoing radical prostatectomy. CLINICAL TRIAL REGISTRATION: NCT03212456.