title: Persistent Pain after Breast Cancer Treatment: A Questionnaire-Based Study on the Prevalence, Associated Treatment Variables, and Pain Type.
abstract: OBJECTIVE
  Persistent pain is a common side effect of breast cancer treatment. The present study aimed to assess the prevalence, associated treatment-related factors, and the type of pain (neuropathic or nociceptive) in patients who had undergone a unilateral mastectomy.
  
  
  METHODS
  All women who underwent a unilateral mastectomy at a University Hospital between 2009 and 2013 were eligible for inclusion. Women with breast reconstruction or active cancer were excluded. Participants were mailed a questionnaire evaluating the prevalence, location, intensity, and frequency of surgical site pain. Additionally, the painDETECT®, a validated instrument to evaluate neuropathic pain, was mailed to all participants.
  
  
  RESULTS
  A total of 305 women were included, and of them, 261 (85.6%) completed the study questionnaire. After a median follow-up period of 3.0 years, 100 women (38.3%) reported experiencing pain at the surgical site. Body mass index ≥30 kg/m2, radiation therapy, and axillary lymph node dissection were significantly associated with persistent pain in univariate models. However, only body mass index ≥30 kg/m2was independently associated with persistent pain (odds ratio, 2.13; 95% confidence interval, 1.06-4.27;p=0.034) in a multivariate analysis. Of the patients reporting pain, 71.0% were unlikely to have a neuropathic pain component. A moderate, but highly significant, positive correlation was observed between the pain intensity and the painDETECT® score (rs=0.47,p<0.001).
  
  
  CONCLUSIONS
  Persistent pain after breast cancer treatment continues to have a high prevalence. Our results indicate that the largest proportion of patients experiencing persistent pain after breast cancer treatment do not have a clear neuropathic pain component.
authors.affiliation: Plastic Surgery Research Unit, Department of Plastic and Breast Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Alexander Andersen
authors.initials: AA
authors.lastname: Juhl
authors.affiliation: Plastic Surgery Research Unit, Department of Plastic and Breast Surgery, Aarhus University Hospital, Aarhus, Denmark.; Department of Surgery, Randers Regional Hospital/Aarhus University Hospital, Aarhus, Denmark.; Danish Breast Cancer Cooperative Group, Denmark.
authors.forename: Peer
authors.initials: P
authors.lastname: Christiansen
authors.affiliation: Plastic Surgery Research Unit, Department of Plastic and Breast Surgery, Aarhus University Hospital, Aarhus, Denmark.
authors.forename: Tine Engberg
authors.initials: TE
authors.lastname: Damsgaard
keywords: Breast neoplasms; Chronic pain; Mastectomy; Neuralgia