Chronic Pain After Breast Surgery: A Prospective, Observational Study

Abstract

Background: Chronic pain is an important complication of breast surgery, estimated to affect 20-30% of patients. We prospectively examined surgical, demographic, and psychosocial factors associated with chronic pain 6 months after breast surgery.

Methods: Patients undergoing breast surgery for benign and malignant disease preoperatively completed validated questionnaires to assess baseline pain and psychosocial characteristics. Pain at 6 months was quantified as the Pain Burden Index (PBI), which encompasses pain locations, severity, and frequency. Surgical type was categorized as breast-conserving surgery (BCS), mastectomy, and mastectomy with reconstruction; axillary procedure was categorized as no axillary surgery, sentinel lymph node biopsy (SLNB), and axillary dissection. PBI was compared between groups using one-way analysis of variance (ANOVA) or Kruskal-Wallis ANOVA, and the relationship between baseline demographic and psychosocial factors and PBI was assessed using Spearman's Rank Correlation. p < 0.05 was considered significant.

Results: PBI was variable amongst patients reporting this endpoint (n = 216) at 6 months, but no difference was found between primary breast surgical types (BCS, mastectomy, and mastectomy with reconstruction) or with surgical duration. However, axillary dissection was associated with higher PBI than SLNB and no axillary procedure (p < 0.001). Younger age (< 0.001) and higher BMI (p = 0.010), as well as higher preoperative anxiety (p = 0.017), depression (p < 0.001), and catastrophizing scores (p = 0.005) correlated with higher 6-month PBI.

Conclusions: Amongst surgical variables, only axillary dissection was associated with greater pain at 6 months after surgery. Patient characteristics that were associated with higher PBI included lower age and higher BMI, as well as higher baseline anxiety, depression, and catastrophizing.

FIGURE 1:

A Pain Burden Index (PBI) at 6 months after surgery in 3 surgical categories (breast conservation, mastectomy, mastectomy with reconstruction) (F=0.173, p=0.841). B PBI at 6 months according to axillary surgery (no axillary surgery, sentinel lymph node biopsy, axillary lymph node dissection) to Pain Burden Index at 6 months (F= 9.302, p<0.001). C PBI at 6 months according to cancer stage or indication for surgery (F=3.168, p=0.009).

FIGURE 2:

A Correlation of baseline PROMIS depression score to Pain Burden Index (PBI) at 6 months (Spearman ρ=0.259, p<0.001). B Correlation of baseline PROMIS anxiety score to PBI at 6 months (Spearman ρ=0.162, p=0.017). C Correlation of baseline pain catastrophizing (PCS) to PBI at 6 months (Spearman ρ=0.191, p=0.005).