Predictive factors for the development of persistent pain after breast cancer surgery

Previous studies have reported that 15-25% of patients treated for breast cancer experience long term moderate to severe pain in the area of surgery, potentially lasting for several years. Few prospective studies have included all potential risk factors for the development of persistent pain after breast cancer surgery (PPBCS). The aim of the present prospective cohort study was to comprehensively identify factors predicting PPBCS. Patients scheduled for primary breast cancer surgery were recruited. Assessments were conducted preoperatively, the first 3 days postoperatively and 1 week, 6 months and 1 year after surgery. A comprehensive validated questionnaire was used. Handling of the intercostobrachial nerve (ICBN) was registered by the surgeon. Factors known by the first 3 weeks after surgery were modelled in ordinal logistic regression analyses. 537 patients with baseline data were included and 475 (88%) were available for analysis at 1 year. At 1 year follow up, the prevalence of moderate to severe pain at rest was 14% and during movement was 7%. Factors associated with pain atrest was age <65 years (OR: 1.8, p=0.02), breast conserving surgery (OR: 2.0, p=0.006), axillary lymph node dissection with preservation of the ICBN (OR: 3.1, p=0.0005), moderate to severe preoperative pain (OR: 5.7, p=0.0002), acute postoperative pain (OR: 2.8, p= 0.0018) and signs of neuropathic pain at 1 week OR: 2.1, p=0.01. Higher preoperative diastolic blood pressure was associated with reduced risk of PPBCS (OR 0.98 per mmHg, p=0.01). Both patient and treatment related risk factors predicted PPBCS. Identifying patients at risk may facilitate targeted intervention.