(248) Acute and subacute postoperative pain after partial and total mastectomy: association with prospectively assessed psychosocial and psychophysical variables

Abstract

Breast cancer is the most common form of female cancer, the treatment of which often involves surgery. Previous reports cite persistent post mastectomy pain (PPMP) incidence around 30%, and putative risk factors include younger age, type of surgery, axillary dissection, anesthetic technique, genetics, negative affect (psychosocial factors) and increased pain sensitivity (psychophysical factors). However, most previous studies of PPMP have been retrospective and cross sectional in design. In the current study, a broad array of potential risk factors were assessed in women prospectively before surgery. Patients undergoing partial or total mastectomy were recruited and underwent preoperative assessment including psychosocial (anxiety, depression, catastrophizing, sleep disturbance etc) and psychophysical (quantitative sensory testing; pressure tolerance, pressure threshold, pinprick temporal summation). Their degree of surgically related pain was then assessed using the Breast Cancer Pain Questionnaire, including frequency, severity and number of body areas assessments to determine a pain burden index (PBI) at several points up to 1 year after surgery. Patients undergoing more extensive surgery reported higher acute pain (postoperative day 0 and 1), with severity correlating with surgical extent (bilateral mastectomy> unilateral mastectomy> lumpectomy), as well as younger age, and higher preoperative psychosocial dysfunction (high catastrophizing, anxiety, depression). Subacute postoperative pain (postoperative day 14) also correlated with younger age and preoperative psychosocial dysfunction, but not surgical extent and duration. By 90 days after surgery, PBI was no longer associated with age or surgical factors, but remained correlated with preoperative psychosocial factors, as well as heightened baseline sensory processing (higher temporal summation of pain and painful aftersensations). These findings suggest that the factors influencing acute pain after surgery may differ somewhat from those that predict more persistent pain. By more extensively phenotyping individual differences in pain processing in the preoperative period, we may identify those at greater risk of chronic postsurgical pain.