title: Neuropathic pain after breast cancer treatment and its impact on sleep quality one year after cancer diagnosis.
abstract: OBJECTIVE
  Data regarding the impact of breast cancer treatment-related neuropathic pain (NP) on sleep quality are scarce. Therefore, we aimed to assess the impact of breast cancer treatment-related NP on patients' sleep quality, during the first year after cancer diagnosis.
  
  
  METHODS
  A total of 501 breast cancer patients were followed prospectively. Incident NP was identified through systematic evaluations after treatments and one year after enrolment. NP severity was quantified using the Brief Pain Inventory severity subscale and sleep quality was evaluated through the Pittsburgh Sleep Quality Index (PSQI), at baseline and after one year. Adjusted regression coefficients (β) and 95% confidence intervals (95%CI) were used to quantify the relation between NP and the variation in the PSQI z-scores.
  
  
  RESULTS
  The occurrence of NP was associated with a deterioration in sleep quality during the first year of follow-up, more pronounced among those with good sleep quality (PSQI≤5) than those with poor sleep quality at baseline (PSQI>5) (β = 0.44, 95%CI: 0.11 to 0.77 versus β = 0.33, 95%CI: 0.08 to 0.59). These differences were accentuated when only the cases of NP with greater severity were considered (β = 0.86, 95%CI: 0.37 to 1.35 versus β = 0.31, 95%CI: -0.08 to 0.64). Within the PSQI components, daytime dysfunction and sleep duration were the most impaired by NP.
  
  
  CONCLUSIONS
  Our findings highlight the importance of the promotion of sleep hygiene among breast cancer patients diagnosed with NP, especially among those with good sleep quality before treatments.
authors.affiliation: ISPUP - EPIUnit, Universidade do Porto, Porto, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Fontes
authors.affiliation: ISPUP - EPIUnit, Universidade do Porto, Porto, Portugal; Centro de Medicina do Sono - Hospital CUF Porto, Porto, Portugal.
authors.forename: Marta
authors.initials: M
authors.lastname: Gonçalves
authors.affiliation: ISPUP - EPIUnit, Universidade do Porto, Porto, Portugal; Instituto Português de Oncologia do Porto, Porto, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Pereira
authors.affiliation: ISPUP - EPIUnit, Universidade do Porto, Porto, Portugal; Departamento de Ciências da Saúde Pública e Forenses e Educação Médica, Faculdade de Medicina, Universidade do Porto, Porto, Portugal. Electronic address: nlunet@med.up.pt.
authors.forename: Nuno
authors.initials: N
authors.lastname: Lunet
mesh_terms: D024221:Antineoplastic Protocols; D001943:Breast Neoplasms / Q000503:physiopathology / Q000628:therapy*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D000069451:Long Term Adverse Effects / Q000453:epidemiology / Q000209:etiology*; D008875:Middle Aged; D009437:Neuralgia / Q000453:epidemiology / Q000209:etiology*; D010147:Pain Measurement; D011446:Prospective Studies; D011788:Quality of Life; D012720:Severity of Illness Index; D012890:Sleep / Q000502:physiology; D012893:Sleep Wake Disorders / Q000453:epidemiology / Q000209:etiology*; D011795:Surveys and Questionnaires; D013997:Time Factors
keywords: Breast neoplasm; Neuropathic pain; Quality of life; Sleep