Management of Cancer-Related Pain With Intrathecal Drug Delivery: A Systematic Review and Meta-Analysis of Clinical Studies

Background: Despite increased attention paid to assessment and management, pain continues to be a prevalent and under-treated symptom in patients with cancer. Intrathecal drug delivery (IDD) is a therapeutic option that allows targeted delivery of analgesics to the intrathecal space. Objective: The aim of this review was to examine the efficacy of managing cancer-related pain with IDD. Secondary objectives included the effects of IDD on systemic opioid use and infection rates. Evidence Review: A systematic search of the literature published between 1990 and 2019 was performed to identify studies evaluating the efficacy and/or safety of IDD with external or implanted pumps in patients with cancer-related pain. Data were extracted and meta-analyses performed to determine the mean changes in pain levels at short-, mid-, and long-term intervals; changes in opioid (oral morphine equivalent [OME]) daily dose; and infection rates. Changes were assessed compared with baseline. Findings: Pain levels were decreased from baseline: On a 0 to 10 scale, mean differences were -4.34 (95% CI [-4.93 to -3.75], p < 0.001) at 4 to 5 weeks; -4.34 (95% CI [-5.07 to -3.62], p < 0.001) at 6 to 12 weeks; and -3.32 (95% CI [-4.60 to -2.04], p < 0.001) at >6 months. Weighted mean OME consumption was reduced by 308.24 (SE = 22.72) mg/d. Weighted mean infection rates were similar to 3% for external and implanted pumps. Conclusions: Meta-analyses show a statistically significant and sustained decrease in cancer pain with IDD, compared with baseline. Systemic opioid consumption was reduced on average by >50% after IDD. Infection rates were comparable with other indications.