Preoperative c-reactive protein predicts next-day pain after breast tumor surgery

Abstract

Introduction/Objective. Subclinical inflammation is increasingly recognized as a driver of postoperative pain, yet its role in breast tumour surgery is not fully defined. The objective was to determine whether preoperative C-reactive protein (CRP) or erythrocyte sedimentation rate (ESR) predict acute postoperative pain (APSP); to examine how surgical extent influences the peri-operative inflammatory response; and to explore the relation between intra-operative fentanyl and pain intensity. Methods. In a prospective single-centre cohort, 101 adults scheduled for breast surgery were stratified into four groups: mastectomy (M, n = 25), tumourectomy (T, n = 28), tumourectomy plus axillary dissection (T+A, n = 20), and benign excision (C, n = 28). Venous blood was drawn on admission (T0) and at 24 h (T24) for CRP and ESR. Pain was assessed with an 11-point Numerical Rating Scale 30 min after recovery and at 24 h; the highest 24-h score (max-APSP) was the primary pain outcome. Results. Pre-operative CRP correlated with max-APSP (p = 0.043), whereas ESR did not (p = 0.11). Baseline CRP and ESR, and their 24-h increments, rose stepwise with surgical magnitude, peaking after mastectomy (baseline CRP 7.1 ± 1.9 mg/L; T24 27.5 ± 3.6 mg•L/¹; both p < 0.01 vs. other groups). Intra-operative fentanyl correlated with CRP at 24 h (r = 0.33, p = 0.001) and with max-APSP (r = 0.28, p = 0.005). Despite these biological gradients, mean max-APSP remained mild to moderate across groups. Conclusion. Pre-surgical systemic inflammation, reflected by CRP, independently predicts early pain after breast tumour surgery. Surgical magnitude amplifies inflammatory markers, and greater fentanyl exposure parallels both inflammation and pain. Routine perioperative CRP may help identify high-risk patients for targeted anti-inflammatory and opioid-sparing analgesic strategies to reduce acute pain and potentially mitigate chronic pain development.