Association between sensory dysfunction and pain 1 week after breast cancer surgery: a psychophysical study.

BACKGROUND

Breast cancer patients treated with axillary lymph node dissection (ALND) have a higher risk of both acute and persistent pain than those treated with sentinel lymph node biopsy (SLNB). This could be attributed to a higher risk of nerve injury with ALND. We hypothesized that (1) pain patients have more pronounced sensory dysfunction than pain-free patients, (2) ALND have more sensory dysfunction and pain than SLNB patients and (3) patients with preserved intercostobrachial nerve (ICBN) preservation have less sensory dysfunction compared to a sectioned ICBN.

METHODS

Twenty-seven patients treated with ALND and 27 with SLNB examined with a standardized Quantitative Sensory Testing (QST) protocol, including sensory mapping, mechanical and thermal thresholds, as well as recording intraoperative ICBN handling and pain status 1 week post-operative.

RESULTS

The area of cold hypoaesthesia was significantly associated with movement-related pain (P = 0.004), with a similar tendency for warmth (P = 0.018) and brush (P = 0.030) hypoaesthesia areas. 14 (26%) of the patients had moderate/severe pain at rest and 13 (24%) during movement without differences between ALND and SLNB, but ALND was associated with more sensory dysfunction than SLNB. Patients with sectioned ICBN reported lower pain intensity than those with preserved ICBN (P = 0.005), but without differences in sensory dysfunction.

CONCLUSION

Pain was increased in patients having larger areas of hypoaesthesia and reduced in patients where ICBN-section was done. Sensory dysfunction was related to extent of axillary surgery, but not with ICBN handling. Our data suggest that acute pain after breast cancer surgery may be related to nerve injury.