Sociodemographic Predictors of Stage IV Breast Cancer Presentation in a Vulnerable Patient Population.

PURPOSE/OBJECTIVE(S) Socially disadvantaged populations in the United States experience worse outcomes compared to the general population when diagnosed with breast cancer. One potentially vulnerable population includes patients under age 65 that qualify for Medicare due to debilitation. This group includes patients who have received social security disability insurance for at least 2 years and those who have been diagnosed with end-stage renal disease or amyotrophic lateral sclerosis; current literature suggests this population experiences worse oncologic outcomes. The National Cancer Database (NCDB) was analyzed to determine what factors among patients under the age of 65 who qualify for Medicare predict for a higher likelihood of presenting with stage IV breast cancer. MATERIALS/METHODS The NCDB was queried for breast cancer patients diagnosed from 2004-2014 who were below the age of 65 and qualified for Medicare. Patients were excluded if they presented with noninvasive disease or if their AJCC stage was unknown. Patients were excluded if any social determinants (race, income quartiles, Charlson-Deyo comorbidity score, travel distance) or hospital factors (facility type, facility location) were unknown. Pearson chi-square test was used to identify associations between categorial variables and stage. Univariate analysis of sociodemographic factors was performed. Statistically significant factors were included in a multinomial logistic regression model to determine independent covariates associated with stage IV presentation. RESULTS 56,964 patients met study criteria. Based on P values (P < 0.05) and strength of odds ratios, the following variables were included in the final model: race, income, comorbidity score, travel distance, facility type, and facility location. All covariates except facility location and distance were significant predictors of metastatic disease presentation. Race was a significant predictor, with white patients less likely to have stage IV presentation (OR 0.73, P < 0.001) compared to black patients. Individuals earning < $38,000 annually were significantly more likely to present at stage IV (OR 1.15, P < 0.001). Patients who traveled shorter distances to treatment facility had non-significantly higher odds of presenting at stage IV (OR 1.37, P = 0.608). Higher comorbidity score was a significant predictor of Stage IV disease at presentation. CONCLUSION Multiple sociodemographic factors were powerful predictors of a stage IV breast cancer presentation in this select population of patients under 65 years old who qualify for Medicare due to debilitation. A deeper understanding of these factors can help identify patients at high risk of a metastatic cancer presentation in order to provide screening and preventative services at an earlier stage in this vulnerable population.