Disparities in management of cancer-related pain: A systematic review.

Abstract

174 Background: Despite well-documented disparities in cancer pain management, downstream clinical consequences of these disparities remain poorly understood. Prior literature has focused largely on identifying inequities in pain treatment and opioid access, with limited synthesis of the resulting clinical outcomes. We conducted a systematic review to characterize symptom burden, healthcare utilization, treatment-related outcomes, and safety outcomes linked to cancer pain management disparities among U.S. adults with cancer. Methods: We conducted PRISMA-guided searches on MEDLINE, Embase, and CINAHL for U.S.-based studies published between 2004-2024. Two reviewers independently screened and coded studies evaluating cancer pain management disparities among adults (18+ years). We synthesized findings using thematic categorization of determinants and clinical outcomes, excluding non-English, pediatric, non-U.S., and interventional studies. Results: Of 3,921 identified articles, 61 met inclusions. Most were retrospective cohort studies (46 [75%]), followed by cross-sectional (10 [16%]) and prospective cohort studies (5 [8%]). Most examined opioid use and management (55 [90%]), opioid disparities (46 [75%]), and clinical outcomes (30 [49%]). Disparities in opioid access, pain management, and outcomes were most often associated with race/ethnicity (22 [36%]), socioeconomic/insurance status (14 [23%]), age/sex (14 [23%]), comorbidity burden (10 [16%]), psychosocial/behavioral issues (9 [15%]), and cancer factors (cancer type, stage, and treatment modality; 6 [10%]). Across studies, intersecting demographic, socioeconomic, clinical, and behavioral factors were linked to delayed opioid prescribing, undertreated pain, and reduced adherence to pain regimens. Collectively, limited access to timely and adequate pain management may act as a mediating driver of downstream adverse outcomes, linking disparities in opioid access to increased symptom burden (e.g., sleep disturbance, constipation, nausea), reduced access to supportive care services and symptom-directed medications, greater healthcare utilization, and higher rates of safety-related adverse events, including falls, opioid overdose, and mortality. Conclusions: In this systematic review, disparities in opioid access and cancer pain management were consistently associated with greater symptom burden, increased healthcare utilization, and worse clinical and safety outcomes among underserved populations. These findings highlight that inequities in pain management extend beyond inadequate symptom control and represent an important intermediary driver of downstream adverse outcomes. By exploring how disparities in cancer pain management translate into measurable clinical burden, our review provides a framework for equity-focused interventions to improve cancer pain management.