Alteration in pain modulation in women with persistent pain after lumpectomy: influence of catastrophizing.

CONTEXT: Persistent pain is common after surgical treatment of breast cancer, but fairly little is known about the changes in sensory processing that accompany such pain syndromes.
OBJECTIVES: This study used quantitative sensory testing to compare psychophysical responses to standardized noxious stimulation in two groups of women who had previously undergone breast cancer surgery: women with (n=37) and without (n=34) persistent postoperative pain.
METHODS: Participants underwent a single testing session in which responses to a variety of noxious stimuli were assessed.
RESULTS: Findings suggested that women with chronic pain after breast cancer surgery display enhanced temporal summation of mechanical pain, deficits in endogenous pain inhibition, and more intense painful aftersensations compared with those without long-term pain. Some of these group differences were mediated by higher levels of pain catastrophizing in the group of women with persistent pain.
CONCLUSION: These findings suggest that persistent postoperative pain is associated with alterations in central nervous system pain-modulatory processes. Future treatment studies might benefit from targeting these pain-modulatory systems, and additional studies using functional neuroimaging methods might provide further valuable information about the pathophysiology of long-term postsurgical pain in women treated for breast cancer.