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

Despite increased attention paid to assessment and management, pain continues to be a prevalent and undertreated symptom in patients with cancer. Intrathecal drug delivery (IDD) is a therapeutic option that allows targeted delivery of analgesics to the intrathecal space.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.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.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 ∼3% for external and implanted pumps.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.