Abstract 1765: Comorbidities contribute to breast cancer disparities among African-American and Hispanic women
Authors: Sarkissyan Marianna , Wu Yanyuan , Vadgama Jaydutt V. 
Published: July 2016

Background: Comorbidities may influence health outcomes from breast cancer and can significantly contribute to health disparities. Studies examining the association of specific comorbidities with breast cancer outcomes in underrepresented African-American and Hispanic women have been few. Notably, underrepresented women are more likely to have comorbidity. Presence of comorbidity may impact not only breast cancer risk and progression, but also likelihood to complete treatment and therapy. Therefore, the aims of the present study are to evaluate comorbidity and breast cancer among African-American and Hispanic women. In addition, the study will assess the consequence of comorbidity on therapy completion and breast cancer survival.

Methods: The study included a cross-sectional cohort of 426 African-American and Hispanic women from South Los Angeles. Personal and medical history was obtained during the informed consent process and from post-hoc medical chart. The results were evaluated using the chi-square test and logistic regression with multivariate analysis. Five year disease free survival analysis (DFS) was performed using Kaplan-Meier survival curves with log rank test. The two-sided P-value less than 0.05 was considered significant.

Results: Our study identified a high frequency of comorbidity among women with breast cancer compared with women without breast cancer (55% vs.45%, respectively: P = 0.032). Diabetes was also more frequent among breast cancer patients than non-cancer participants (62% vs. 38%; P = 0.005). African-American women were more likely than Hispanic women to have comorbidity (P = 0.003), particularly hypertension and hypertension with diabetes. Hispanic women were more likely to have diabetes only. In univariate analysis, the presence of any comorbidity was significantly associated with breast cancer (OR = 1.536; 95% CI = 1.045-2.255; P-value = 0.029). In the adjusted multivariate model, this association was borderline significant (P-Value = 0.057). The association of compound comorbidity (diabetes with hypertension) was significant in both the univariate and multivariate models (OR = 3.333; 95% CI = 1.290-8.611; P-Value = 0.013). Women with an increasing number of comorbidities were increasingly less likely to complete treatment with chemotherapy (P = 0.022). African-American women with compound comorbidity were least frequently able to complete treatment with chemotherapy (P = 0.002). Lastly, women who completed treatment with chemotherapy had a significantly higher survival vs. women who did not complete (Log rank = 5.09; P = 0.024).

Conclusions: The presence of comorbidity can affect risk of breast cancer, likelihood of completion of therapy, and subsequent survival. African-American and Hispanic women have higher frequency of comorbidities and this may place women, especially with compound comorbidity, at a greater risk for breast cancer and lower survival outcomes.

Citation Format: Marianna Sarkissyan, Yanyuan Wu, Jaydutt V. Vadgama. Comorbidities contribute to breast cancer disparities among African-American and Hispanic women. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 1765.