The impact of pain and opioids use on survival in cancer patients: Results from a population-based cohort study and a meta-analysis.

The study aimed to explore whether cancer-related pain and opioids use are associated with the survival of cancer patients, and perform a cohort study and a meta-analysis to quantify the magnitude of any association.A retrospective cohort study was performed to analyze the impact of pain level, and opioids use on cancer-specific survival (CSS) in advanced cancer patients. Patients and relevant medical records were selected from the registry of the Radiation and chemotherapy division of Ningbo First Hospital between June 2013 and October 2017. Hazard ratios (HRs) and 95% confidential intervals (CIs) for CSS by opioids use were calculated by univariate and multivariate Cox regression analyses. The systematic review included relevant studies published before October 2018. The combined HRs and 95% CIs for overall survival (OS) and progression-free survival (PFS) were calculated using random-effect models.A total of consecutive 203 cancer patients were included in the cohort study. Kaplan-Meier curves indicate a negative association between CSS and cancer-related pain or opioids requirement, but less evidence of an association with the dose of opioids use. Multivariate models revealed that the pain level and opioids requirement were associated with shorter CSS, after adjusting for significant covariates. The results of the meta-analysis indicated that postoperative opioids use had a poor effect on PFS, and opioids use for cancer-related pain was associated with poor OS in cancer patients, while intraoperative opioids use was not associated with cancer survival.We concluded that cancer-related pain and opioids requirements are associated with poor survival in advanced cancer patients, and postoperative opioids use and opioids use for cancer-related pain may have an adverse effect on the survival of cancer patients.