Abstract B120: Hospitalization may be an early indicator of worse breast cancer survival among women from disparate populations
Authors: Connor Avonne E , May Betty , Schmaltz Chester , Jackson-Thompson Jeannette , Visvanathan Kala 
Published: September 2020

Abstract
Background: Missouri is burdened by high breast cancer (BC) mortality rates, particularly among women from disparate populations (individuals living in poverty, rural areas, and African Americans). In a prior study, we found that women diagnosed with BC from disparate populations have a high prevalence of comorbidities and these commonly diagnosed comorbidities were associated with worse BC prognosis. We now hypothesize that the frequency of hospitalizations may be an early indicator of increased mortality and may be used to identify at risk BC patients with co-morbid conditions. Methods: Women age 18+ diagnosed with invasive BC in Missouri during 2004–2012 were identified from the Missouri Cancer Registry. Data were merged with hospital discharge data from the state Patient Abstract System. A comorbidity score was constructed to reflect the number of inpatient admissions for the 3 most prevalent conditions (Type-2 diabetes, hypertension, and CVD) among patients. We identified women who experienced an inpatient hospitalization &gt; 1 year after their BC diagnosis to ensure hospitalizations were not due to reasons associated with their primary BC diagnosis. For risk of BC mortality, adjusted hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox proportional hazards regression models overall and stratified by race, poverty level, rural/urban residence, and age. Results: A total of 36,581 women with incident invasive BC and comorbidity data at the time of BC diagnosis were analyzed. After a median follow-up time of 78 months, 11,102 deaths occurred, of which 6,232 were BC deaths. Approximately 31% of patients had ≥1 comorbidity and 17% had been hospitalized once. Increasing number of comorbidities was significantly associated with the likelihood of being hospitalized after BC diagnosis (p-trend &lt; 0.001). BC patients with ≥ 5 hospitalizations post diagnosis compared to no hospitalization after adjusting for comorbidities and prognostic factors had increased BC mortality risk (HR, 2.62; 95% CI 2.31-2.97). Having just one hospitalization significantly increased the risk of BC death by 34% compared to women without a hospitalization. In stratified analyses, we observed significant differences in associations between hospitalizations and BC mortality by race (p=0.02), residential location (p &lt; 0.01), and age (p &lt; 0.001). Women &lt; 50 years of age and with ≥ 5 hospitalizations had over 600% increase in risk of BC death (HR, 6.51; 95% CI 5.12-8.29) compared to women &lt; 50 years without hospitalizations. Among women with ≥ 1 comorbidity, ≥ 5 hospitalizations increased risk of BC death by 83% (HR, 1.83; 95% CI 1.54-2.17) compared to women without a hospitalization. Conclusion: BC patients who have comorbidities and experience a hospitalization post diagnosis are at increased risk of BC mortality. Further, hospitalizations could be used to identify high risk survivors that could benefit from targeted interventions. Analyses evaluating diseases contributing to hospitalizations are ongoing.
Citation Format: Avonne E Connor, Betty May, Chester Schmaltz, Jeannette Jackson-Thompson, Kala Visvanathan. Hospitalization may be an early indicator of worse breast cancer survival among women from disparate populations [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr B120.