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.

Surgical versus Nonsurgical Management of Postmastectomy Lymphedema: A Prospective Quality of Life Investigation

“…Though race and age have previously been linked to incidence of secondary lymphedema in the literature, the impact of such sociodemographic factors on lymphedema QoL outcomes is largely unknown. 29,30 However, African American race and older age have been linked to poor QoL outcomes in other chronic disease conditions, and may reflect underlying social and health disparities. 31,32 Further study is needed to better characterize the impact of sociodemographic factors on lymphedema outcomes.…”

Breast Cancer–Related Lymphedema in Hispanic Women: A Phenomenological Study

“…The delay in medical care is primarily due to lack of insurance, lack of health care access, and cultural beliefs (Tejeda, Gallardo, Ferrans, & Rauscher, 2017). In a prospective cohort study of 2,953 women with breast cancer, Kwan et al (2016) noted a nearly twofold risk of BCRL among nonobese Hispanic women.…”

Strategic recruitment of an ethnically diverse cohort of overweight survivors of breast cancer with lymphedema

“…Although black women historically are less likely than white women to be diagnosed with breast cancer, breast cancer‐specific mortality rates remain higher among black compared with white women . Furthermore, black women are more likely to experience common adverse effects of cancer treatment, including breast cancer‐related lymphedema (BCRL) . Finally, knowledge regarding lymphedema varies across the population of survivors of breast cancer, with low educational level and black race found to be predictive of lower awareness of this chronic condition .…”

“…2,3 Furthermore, black women are more likely to experience common adverse effects of cancer treatment, 4,5 including breast cancer-related lymphedema (BCRL). [6][7][8][9] Finally, knowledge regarding lymphedema varies across the population of survivors of breast cancer, with low educational level and black race found to be predictive of lower awareness of this chronic condition. 10 As such, black women may particularly benefit from research regarding interventions to improve lymphedema and breast cancer recurrence risk, but may be less likely to know that they have the condition.…”