Abstract 4630: Eleven specific comorbidities and mortality risk in women diagnosed with invasive breast cancer between the ages of 35 and 64 years
Authors: Ma Huiyan , Ursin Giske , Malone Kathleen E. , Simon Michael S. , McDonald Jill A. , Strom Brian L. , Press Michael F. , Bernstein Leslie , Lu Yani 
Published: September 2020

Abstract
Purpose: To evaluate the impact of 11 specific comorbidities on mortality risk in women diagnosed with breast cancer between the ages of 35 and 64 years.
Methods: We followed 4,485 women, ages 35 to 64 years when diagnosed with first primary invasive breast cancer between 7/1/94 and 4/30/98, to determine if subsequent mortality risk was affected by self-reported history of 11 comorbidities diagnosed before their breast cancer (previous cancer; diabetes; rheumatoid arthritis; myocardial infarction; other types of heart disease; hypertension; stroke; phlebitis, pulmonary embolism, or blood clots in legs or lungs; gallbladder disease; peptic, stomach, gastric, or duodenal ulcer; liver disease). During follow up (average 10.1 years), 1,234 women died (904 breast cancer deaths). Multivariable Cox proportional hazards regression models were fit to data to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for breast cancer-specific mortality and mortality due to other causes.
Results: Approximately 50% of women reported a history of having at least one of the 11 comorbidities. The total number of comorbidities a woman had was not associated with breast cancer-specific mortality risk (p-trend=0.43), but it was positively associated with risk of mortality due to other causes (p-trend&lt;0.0001). The positive association was not modified by race, education, household income, menopausal status, body mass index, history of alcohol consumption or cigarette smoking history (all p-heterogeneity ≥ 0.13). No individual comorbidity was associated with breast cancer-specific mortality whereas a history of previous cancer, diabetes, or myocardial infarction was associated with increased risk of mortality due to other causes (HRs: 1.73, 2.13, and 2.11, respectively). Women with a history of diabetes who also had a history of previous cancer or a history of myocardial infarction experienced an 8-fold greater risk of mortality due to other causes than women without any comorbidity (HR=8.01, 95% CI=4.50-14.26).
Conclusions: Our findings among women diagnosed with invasive breast cancer between the ages of 35 and 64 years suggest that the total number of comorbidities and specifically history of previous cancer, diabetes, or myocardial infarction increased the risk of dying from causes other than breast cancer, especially when having a history of diabetes as well as previous cancer or myocardial infarction. These results indicate the importance of interventions to reduce the impact of comorbidities among breast cancer survivors.
Citation Format: Huiyan Ma, Giske Ursin, Kathleen E. Malone, Michael S. Simon, Jill A. McDonald, Brian L. Strom, Michael F. Press, Leslie Bernstein, Yani Lu. Eleven specific comorbidities and mortality risk in women diagnosed with invasive breast cancer between the ages of 35 and 64 years [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4630.