Risk factors associated with chronic pain after mastectomy: a prospective study with a 5-year follow-up in Japan.

[BACKGROUND] Chronic pain is a major complication following breast surgery including breast reconstruction. We previously examined prospective patient-specific and medical/surgical factors that predict chronic pain a year after breast surgery in the Japanese population. Five-year survivorship is essential for breast cancer patients. This report is a 4-year follow-up study following the previous research.

[METHODS] A follow-up observation study was performed 5 years after breast operations. The subjects were patients who underwent breast surgery, including tissue expander/implant (TE/implant), DIEP procedures and mastectomy only. Pain at 5 years was assessed using the Japanese Version of the Short-Form McGill Pain Questionnaire (SF-MPQ-JV). A multiple linear regression model was used to examine the relationships of clinical factors with chronic pain.

[RESULTS] Questionnaires were completed by 132 subjects. No factor related to chronic pain was significantly related to the MPQ pain ratings. Among patient characteristics, a psychotic or neurological medical history was related to significantly lower visual analog scale (p = 0.02) and present pain index (p = 0.04) scores. A history of chemotherapy and/or hormone therapy was significantly associated with the frequency of use of pain medication postoperatively (p = 0.05) and effect on the social life of the patients (p = 0.02).

[CONCLUSIONS] A psychotic or neurological history and a history of chemotherapy and/or hormone therapy were identified as risk factors for chronic pain after breast surgery, but the type of operation was not associated with chronic pain.