title: Race/ethnicity, genetic ancestry, and breast cancer-related lymphedema in the Pathways Study.
abstract: Breast cancer-related lymphedema (BCRL) is a serious chronic condition after breast cancer (BC) surgery and treatment. It is unclear if BCRL risk varies by race/ethnicity. In a multiethnic prospective cohort study of 2953 BC patients, we examined the association of self-reported BCRL status with self-reported race/ethnicity and estimated genetic ancestry. Hazard ratios (HR) and 95 % confidence intervals (CI) were calculated by multivariable Cox proportional hazards models, with follow-up starting 6 months post-BC diagnosis. Estimates were further stratified by body mass index (BMI). By 48 months of follow-up, 342 (11.6 %) women reported having BCRL. Younger age at BC diagnosis, higher BMI at baseline, and lower physical activity were associated with greater BCRL risk. African American (AA) women had a 2-fold increased risk of BCRL compared with White women (HR = 2.04; 95 % CI 1.35-3.08). African genetic ancestry was also associated with an increased risk (HR = 2.50; 95 % CI 1.43, 4.36). Both risks were attenuated but remained elevated after adjusting for known risk factors and became more pronounced when restricted to the nonobese women (adjusted HR = 2.31 for AA and HR = 3.70 for African ancestry, both p < 0.05). There was also evidence of increased BCRL risk with Hispanic ethnicity in the nonobese women. Nonobese AA women had a higher risk of BCRL than White women, which cannot be fully explained by known risk factors. This is the first large-scale, prospective study demonstrating differences in BCRL risk according to race/ethnicity as assessed by both self-report and genetic ancestry data, with a potential ancestry-obesity interaction.
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, 94612, USA. Marilyn.L.Kwan@kp.org.
authors.forename: Marilyn L
authors.initials: ML
authors.lastname: Kwan
authors.affiliation: Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, 14263, NY, USA.
authors.forename: Song
authors.initials: S
authors.lastname: Yao
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, 94612, USA.
authors.forename: Valerie S
authors.initials: VS
authors.lastname: Lee
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, 94612, USA.
authors.forename: Janise M
authors.initials: JM
authors.lastname: Roh
authors.affiliation: Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, 14263, NY, USA.
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, 94612, USA.
authors.forename: Isaac J
authors.initials: IJ
authors.lastname: Ergas
authors.affiliation: Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, 14263, NY, USA.
authors.forename: Qian
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, 14263, NY, USA.
authors.forename: Yali
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: San Jose Medical Center, Kaiser Permanente Northern California, San Jose, 95119, CA, USA.
authors.forename: Susan E
authors.initials: SE
authors.lastname: Kutner
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, 94612, USA.
authors.forename: Charles P
authors.initials: CP
authors.lastname: Quesenberry
authors.affiliation: Department of Cancer Prevention and Control, Roswell Park Cancer Institute, Buffalo, 14263, NY, USA.
authors.forename: Christine B
authors.initials: CB
authors.lastname: Ambrosone
authors.affiliation: Division of Research, Kaiser Permanente Northern California, Oakland, CA, 94612, USA.
authors.forename: Lawrence H
authors.initials: LH
authors.lastname: Kushi
mesh_terms: D000328:Adult; D001741:Black or African American / Q000235:genetics*; D017668:Age of Onset; D000368:Aged; D015992:Body Mass Index; D000072656:Breast Cancer Lymphedema / Q000453:epidemiology* / Q000208:ethnology* / Q000235:genetics; D005260:Female; D006630:Hispanic or Latino / Q000235:genetics*; D006801:Humans; D008875:Middle Aged; D016016:Proportional Hazards Models; D011446:Prospective Studies; D057566:Self Report; D044465:White People / Q000235:genetics*
keywords: Ancestry; Breast cancer-related lymphedema; Genetics; Interaction; Obesity; Racial disparity