title: A prospective study on the neurological complications of breast cancer and its treatment: Updated analysis three years after cancer diagnosis.
abstract: OBJECTIVE
  To quantify the prevalence of neurological complications among breast cancer patients at one and three years after diagnosis, and to identify factors associated with neuropathic pain (NP) and chemotherapy-induced peripheral neuropathy (CIPN).
  
  
  METHODS
  Prospective cohort study including 475 patients with newly diagnosed breast cancer, recruited among those proposed for surgical treatment (Portuguese Institute of Oncology, Porto). Patients underwent a neurological evaluation and had their cognitive function assesses with the Montreal Cognitive Assessment, before treatment and at one and three years after enrollment. We estimated the prevalence of each neurological complication, and odds ratios (OR), adjusted for socio-demographic and clinical characteristics, to identify factors associated with NP and CIPN.
  
  
  RESULTS
  More than half of the patients [54.7%, 95% confidence interval (95%CI): 50.2-59.2] presented at least one neurological complication, at one or at three years after cancer diagnosis. Between the first and the third year of follow-up, there was an increase in the prevalence of NP (from 21.1% to 23.6%), cognitive impairment (from 7.2% to 8.2%), cerebrovascular disease (from 0.6% to 1.5%) and brain metastasis (from 0.0% to 0.6%). The prevalence of CIPN decreased from 14.1% to 12.6%. Axillary lymph node dissection was associated with NP at one year (OR = 2.75, 95%CI: 1.34-5.63) and chemotherapy with NP at three years (OR = 2.10, 95%CI: 1.20-3.67). Taxane-based chemotherapy was strongly associated with prevalence of CIPN at one and three years.
  
  
  CONCLUSIONS
  Neurological complications are frequent even three years after cancer diagnosis and NP remained the major contributor to the burden of these conditions among survivors.
authors.affiliation: ISPUP-EPIUnit, University of Porto (ISPUP), Rua das Taipas, nº135, 4050-600, Porto, Portugal.
authors.forename: Filipa
authors.initials: F
authors.lastname: Fontes
authors.affiliation: ISPUP-EPIUnit, University of Porto (ISPUP), Rua das Taipas, nº135, 4050-600, Porto, Portugal; Portuguese Institute of Oncology of Porto, Rua Dr. António Bernardino de Almeida, 4200-075, Porto, Portugal.
authors.forename: Susana
authors.initials: S
authors.lastname: Pereira
authors.affiliation: Department of Experimental Biology, Faculty of Medicine, University of Porto, Al. Prof. Hernâni Monteiro, 4200-319 Porto, Portugal; Institute for Molecular and Cell Biology (IBMC), University of Porto, Rua do Campo Alegre, nº823, 4150-180 Porto, Portugal.
authors.forename: José Manuel
authors.initials: JM
authors.lastname: Castro-Lopes
authors.affiliation: ISPUP-EPIUnit, University of Porto (ISPUP), Rua das Taipas, nº135, 4050-600, Porto, Portugal; Department of Clinical Epidemiology, Predictive Medicine and Public Health, Faculty of Medicine, University of Porto, Al. Prof. Hernâni Monteiro, 4200-319, Porto, Portugal. Electronic address: nlunet@med.up.pt.
authors.forename: Nuno
authors.initials: N
authors.lastname: Lunet
mesh_terms: D000328:Adult; D000970:Antineoplastic Agents / Q000009:adverse effects*; D001365:Axilla; D001932:Brain Neoplasms / Q000453:epidemiology / Q000556:secondary; D001943:Breast Neoplasms / Q000150:complications / Q000188:drug therapy* / Q000473:pathology; D001952:Bridged-Ring Compounds / Q000009:adverse effects*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000150:complications / Q000188:drug therapy / Q000473:pathology; D002561:Cerebrovascular Disorders / Q000139:chemically induced / Q000453:epidemiology; D060825:Cognitive Dysfunction / Q000139:chemically induced / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008197:Lymph Node Excision; D008875:Middle Aged; D009437:Neuralgia / Q000139:chemically induced / Q000453:epidemiology*; D020258:Neurotoxicity Syndromes / Q000453:epidemiology* / Q000209:etiology; D010523:Peripheral Nervous System Diseases / Q000139:chemically induced / Q000453:epidemiology*; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D017741:Survivors / Q000706:statistics & numerical data; D043823:Taxoids / Q000009:adverse effects*
chemical_list: D000970:Antineoplastic Agents; D001952:Bridged-Ring Compounds; D043823:Taxoids; C080625:taxane
keywords: Breast neoplasms; Cognition disorders; Nervous system diseases; Neuropathic pain; Phantom limb; Polyneuropathies