Mei-Tzu C. Tang

Supplementary Table 1 presents the distribution of patient characteristics among those with and without extended follow-up for recurrence.

Background:We evaluated the association between metabolic syndrome (MetS; obesity plus two metabolic risk factors) and breast cancer outcomes according to molecular subtype.Methods:This population-based prospective cohort consisted of 3,267 women ages 20 to 69 years diagnosed with a first primary invasive breast cancer from 2004 to 2015 in the Seattle–Puget Sound region. Breast cancer was categorized into three subtypes based on estrogen receptor (ER), progesterone receptor, and HER2 expression: luminal (ER+), triple-negative (ER−/progesterone receptor negative/HER2−), and HER2-overexpressing (H2E; ER−/HER2+) subtypes. We used time-varying Cox models to assess the association of prevalent and incident MetS with risks of recurrence, breast cancer–specific mortality (BCSM), and all-cause mortality (ACM).Results:MetS was associated with a greater risk of recurrence [HR, 3.24; 95% confidence interval (CI), 1.13–9.33] and BCSM (HR, 5.34; 95% CI, 2.32–12.31) only for the H2E subtype and greater risks of ACM for luminal (HR, 1.92; 95% CI, 1.37–2.68), H2E (HR, 5.09; 95% CI, 2.51–10.32), and all cases combined (HR, 1.90; 95% CI, 1.42–2.53). We also observed heterogeneity in recurrence and mortality outcomes across specific components of MetS and molecular subtypes.Conclusions:MetS is associated with ACM among women with breast cancer and with BCSM among women with the H2E subtype.Impact:These results highlight the importance of managing comorbidities to decrease the risk for adverse outcomes among breast cancer survivors.

Supplementary Table 2 presents results for breast cancer recurrence associated with metabolic syndrome and its components by molecular subtype of breast cancer and stratified by age at diagnosis.

Supplementary Table 5 presents results for breast cancer specific and all-cause mortality associated with metabolic syndrome and its components by molecular subtype of breast cancer and stratified by stage at diagnosis.

Supplementary Table 4 presents results for breast cancer recurrence associated with metabolic syndrome and its components by molecular subtype of breast cancer and stratified by stage at diagnosis.

Flow diagram describing collection of comorbidity diagnoses and treatments with respect to breast cancer diagnosis.

Supplementary Table 3 presents results for breast cancer specific and all-cause mortality associated with metabolic syndrome and its components by molecular subtype of breast cancer and stratified by age at diagnosis.

Background: We evaluated the association between metabolic syndrome (MetS; obesity plus two metabolic risk factors) and breast cancer outcomes according to molecular subtype. Methods: This population-based prospective cohort consisted of 3,267 women ages 20 to 69 years diagnosed with a first primary invasive breast cancer from 2004 to 2015 in the Seattle–Puget Sound region. Breast cancer was categorized into three subtypes based on estrogen receptor (ER), progesterone receptor, and HER2 expression: luminal (ER+), triple-negative (ER−/progesterone receptor negative/HER2−), and HER2-overexpressing (H2E; ER−/HER2+) subtypes. We used time-varying Cox models to assess the association of prevalent and incident MetS with risks of recurrence, breast cancer–specific mortality (BCSM), and all-cause mortality (ACM). Results: MetS was associated with a greater risk of recurrence [HR, 3.24; 95% confidence interval (CI), 1.13–9.33] and BCSM (HR, 5.34; 95% CI, 2.32–12.31) only for the H2E subtype and greater risks of ACM for luminal (HR, 1.92; 95% CI, 1.37–2.68), H2E (HR, 5.09; 95% CI, 2.51–10.32), and all cases combined (HR, 1.90; 95% CI, 1.42–2.53). We also observed heterogeneity in recurrence and mortality outcomes across specific components of MetS and molecular subtypes. Conclusions: MetS is associated with ACM among women with breast cancer and with BCSM among women with the H2E subtype. Impact: These results highlight the importance of managing comorbidities to decrease the risk for adverse outcomes among breast cancer survivors.

Supplementary Table 1 presents the risk of locoregional and distant breast cancer recurrence and risk of recurrence to bone, lung, and liver associated with alcohol use at diagnosis, for luminal, triple-negative (TN), and overall breast cancer.

Supplementary Table 1 presents the risk of locoregional and distant breast cancer recurrence and risk of recurrence to bone, lung, and liver associated with alcohol use at diagnosis, for luminal, triple-negative (TN), and overall breast cancer.