title: Risk factors for lymphedema in a prospective breast cancer survivorship study: the Pathways Study.
abstract: OBJECTIVE
  To determine the incidence of breast cancer-related lymphedema (BCRL) during the early survivorship period as well as demographic, lifestyle, and clinical factors associated with BCRL development.
  
  
  METHODS
  The Pathways Study, a prospective cohort study of breast cancer survivors with a mean follow-up time of 20.9 months.
  
  
  METHODS
  Kaiser Permanente Northern California medical care program.
  
  
  METHODS
  We studied 997 women diagnosed from January 9, 2006, through October 15, 2007, with primary invasive breast cancer and who were at least 21 years of age at diagnosis, had no history of any cancer, and spoke English, Spanish, Cantonese, or Mandarin.
  
  
  METHODS
  Clinical indication for BCRL as determined from outpatient or hospitalization diagnostic codes, outpatient procedural codes, and durable medical equipment orders.
  
  
  RESULTS
  A clinical indication for BCRL was found in 133 women (13.3%), with a mean time to diagnosis of 8.3 months (range, 0.7-27.3 months). Being African American (hazard ratio, 1.93; 95% confidence interval, 1.00-3.72) or more educated (P for trend = .03) was associated with an increased risk of BCRL. Removal of at least 1 lymph node (hazard ratio, 1.04; 95% confidence interval, 1.02-1.07) was associated with an increased risk, yet no significant association was observed for type of lymph node surgery. Being obese at breast cancer diagnosis was suggestive of an elevated risk (hazard ratio, 1.43; 95% confidence interval, 0.88-2.31).
  
  
  CONCLUSIONS
  In a large cohort study, BCRL occurs among a substantial proportion of early breast cancer survivors. Our findings agree with those of previous studies on the increased risk of BCRL with removal of lymph nodes and being obese, but they point to a differential risk according to race or ethnicity.
authors.affiliation: Kaiser Permanente Northern California, Oakland, 94612, USA. Marilyn.L.Kwan@kp.org
authors.forename: Marilyn L
authors.initials: ML
authors.lastname: Kwan
authors.forename: Jeanne
authors.initials: J
authors.lastname: Darbinian
authors.forename: Kathryn H
authors.initials: KH
authors.lastname: Schmitz
authors.forename: Rebecca
authors.initials: R
authors.lastname: Citron
authors.forename: Paula
authors.initials: P
authors.lastname: Partee
authors.forename: Susan E
authors.initials: SE
authors.lastname: Kutner
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Kushi
mesh_terms: D001943:Breast Neoplasms / Q000208:ethnology / Q000473:pathology / Q000601:surgery*; D002140:California / Q000453:epidemiology; D016009:Chi-Square Distribution; D003710:Demography; D004522:Educational Status; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008019:Life Style; D008207:Lymphatic Metastasis; D008209:Lymphedema / Q000453:epidemiology* / Q000208:ethnology / Q000209:etiology; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009765:Obesity / Q000150:complications; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D017741:Survivors / Q000706:statistics & numerical data